Tentative titles of the third Riverworld novel. This novel has actually been published with the title The Dark Design (1977).

Announced as follows: "Presently he is working on a second novel for Essex House, And You, Red Judge, to be followed by the continuation of The Image of the Beast, tentatively titled Sketches Among the Ruins of My Mind."
The novels The Image of the Beast and the sequel, Blown, have been published by Essex House, but we never have seen anything anymore of the third announced novel.

For several years there were rumors and bibliographies with information that this sf/pornographic/gothic novel, written under the pseudonym William Norfolk M.D., had been published in 1965 or in 1971 by Rubicon Press. However, this novel was never published.
The fanzine Farmerage published this short article in 1979:

AS YOU DESIRE: THE TRUE STORY by George H. Scheetz Philip José Farmer fans long to acquire one book above all, i.e. As You Desire, by "William Norfolk, M.D." The only reason the book is known at all is because Farmer revealed it himself. This elusive title was written, sold to Rubicon Classics (contract dated 7 July 1969), but never published. Farmer still has a copy of the manuscript. Rubicon sold out to American Art Agency in the early 1970s. Perhaps the original manuscript is still extant. Farmer, however, declines selling it again.

A novel written in collaboration with Randall Garrett in the early fifties. It had been sold to Startling Stories but the magazine folded before the novel got published. The manuscript got lost. Farmer: "I still hope that it will turn up. I might rewrite it and send it out again." 

This novel was written in 1953 and scheduled for serialized publication in the magazine Startling Stories in that year. However Startling Stories gave up its monthly schedule and the novel disappeared until Ballantine published it in 1965 as Dare.
Fantasy-Times: «Farmer's serial, the first in Startling will begin in the October issue. It will be called "A Beast Of The Fields"-and will be in three parts.»

The first tentative title was Why Everybody Hates Me. A mystery novel/near future tale with Kent Lane, the illegitimate son of the Shadow, as hero. Meant to be published by Bobbs-Merrill.

Several times I saw this title mentioned as a to be written sequel to Jesus on Mars, and also often another title appeared with this, Josph Smith on Mercury. But never came an actual announcement of one or both of these titles. So, I am not sure if Farmer ever planned these books seriously as sequels, but they were never written.

Several sources (see also here).
 

Farmer: "A story set in the same world as my short story "The Sliced-Crosswise Only-On-Tuesday World", for Doubleday."
Instead of one novel with the never used title Daybreakers, Farmer wrote three novels: Dayworld (Putnam), Dayworld Rebel (Ace/Putnam) and Dayworld Breakup (Tor).
Another tentative title is The Hole in Wednesday (see under).

Luna Monthly: "Philip José Farmer is doing an original, Death's Dumb Trumpet, for Avon Books; about the necrology of mankind in 1990 when finis is written to our irreversibly polluted planet."
The Burroughs Bulletin: "I'm writing a novel, Death's Dumb Trumpet, about the effects of pollution twenty years from now."

Sources:
- Norris Chapnick in Luna Monthly #9, 1970
- The Burroughs Bulletin #22, Summer 1971
 

Farmer has written the novel Escape From Loki (1991), but he had also ideas and notes for more stories or novels. For instance a sequel to the final Doc Savage story, Up from Earth's Center. Also mentioned are another four tentative titles for stories: Dark Satanic Mills, Bloody Hands, Invisible Nation and The Crimson Jaguar.

Source:
- "Afterword" in Doc Savage - Omnibus #13, 1990
 

"Philip José Farmer has signed to do the novelization of Fantastic Voyage 2, the book which was originally supposed to be written by Isaac Asimov. ... Although the advance was not up to the $1 million + offered Asimov, it was more than a half million dollars, and the highest amount Farmer has ever been offered. ....." 

Source:
- Locus #290, 1985

"The saga of the book version of the unmade movie version of Fantastic Voyage 2 has taken another fantastic turn. Apparently Isaac Asimov, who turned down a $1 million + deal in 1984 as writer, will now, after all, write the book. Meanwhile Philip José Farmer, who accepted a $690,000 deal and wrote two books for it, is out in the cold with only a fraction of the money. .... Farmer was given the 20 page treatment and a $56,000 advance. He wrote a novel following the script and sent it to NAL. His NAL editor, Sheila Gilbert, had moved to DAW and Executive Editor Michaela Hamilton took over. She eventually rejected the manuscript and asked for a rewrite. Farmer turned in a second novel which was based on the ideas but did not slavishly follow the treatment. This too was rejected. .... Farmer commented "Now I wish Putnam hadn't given permission at all. If I were a literary terrorist, I'd blow up Doubleday and NAL!"." 

Source:
- Locus #303, 1986

Fantastic Voyage 2 exists only in manuscript with Farmer.
 

See the 'World of Tiers series' on this page.
 

Farmer planned to write a comic novel based on his experiences in the space-defence industry. Uncle Sam's Mad Tea Party is mentioned as an alternative title.
Several notes by PJF for this book were found in his archives. These notes were published in the fanzine Farmerphile Issue No.12 (2008).

With the publication of part 3 in the Greatheart Silver series, the story "Greatheart Silver in the First Command" was an announcement of a next episode: "Greatheart Silver in The Great Fog, or In Old New York: 1934". This episode was never published however.
Notes on more stories in the series were found in Farmer's archives.

Source:
- Weird Heroes - Volume 6, 1977
- Farmerphile Issue No. 14, October 2008
 

This title was planned as a sequel to The Green Odyssey.

Source:
- Extrapolation Vol.18. No.1, December 1976
 

A tentative title for Dayworld. Another tentative title is called (The) Daybreakers (see above).
Farmer had started a manuscript for this book. The original manuscript was finished by Danny Adams, and the novel, Dayworld: A Hole in Wednesday, was published in 2016.

Source:
- Extrapolation Vol.18. No.1, December 1976
 

Announced for publication by Bobbs-Merrill in the fall of 1975.

Source:
- Locus #169, 1975
 

See with Buddha on Venus on this page.
 

See the 'World of Tiers series' on this page.
 

See the Opar / Khokarsa series on this page. The novel has been announced again, with the new title The Song of Kwasin.
 

"I plan to write three more Doc Caliban-Lord Grandrith novels", said Farmer.
See also The Monster on Hold. 

Source:
- Whizzard Vol.2 #10, Fall 1977
 

Former tentative title: The Unspeakable Treshold.
This will be the latest story in the series 'Lord Grandrith/Doc Caliban' , beginning with A Feast Unknown (1969) and continued in Lord of the Trees (1970) and The Mad Goblin (1970). The first draft of a chapter of this proposed novel has been published as "The Monster on Hold". 

Source:
- PJF's Introduction in World Fantasy Convention 1983, 1983
 

Announced for publication by Ballantine Books in 1973.
Ballantine published this in 1973 with the title Traitor to the Living.

Source:
- Locus #115, June 23, 1972
 

According to one source Farmer planned to write at least three more novels, and according to another source he had originally plans to write from nine to twelve books in the Opar series. This didn't come true mainly because of the low advance and royalties payment for the novels, and also because of the luke response from the readers. Farmer then decided to write a third and final novel, but didn't have the time to write it because of other obligations. The last one had been announced for 1979 with the title Kwasin of Opar. This novel has been completed by Christopher Paul Carey, and announced again in 2008 with the new title The Song of Kwasin.
See series: Opar / Khokarsa.

Sources:
- Science Fiction Review # 14, August 1975
- The foreword in Flight to Opar (DAW, 1976)
- Norwescon 2, March 1979
- Amazing, November 1984
- Heritage of the Flaming God, 1999
 

Formerly titled The Unruly Lance, or The Green Knight. A mainstream novel which takes place in the late 40's or early 50's when the GI's were coming back to college.

Farmer planned to write more stories and novels about Ralph Von Wau Wau, at least enough to fill a collection of stories. Two stories have been published; these were written by 'Jonathan Swift Somers III'. In these stories the following titles have been mentioned as other Ralph Von Wau Wau stories: "The Wonder of the Wandering Wound", "A Short Case of Longevity", "The Caper of Kupper, the Copper's Keeper", "The Case of the Stolen Dreams", "The Adventure of the Tired Color Man", "The Case of the Seeing Eye Man", "The Hind of the Basker-bergs", "The Shakedown of the Shook Sheik", "The Four Musicians of Bremen" and "The Scarletin Letter", plus a novel: Some Humans Don't Stink.

In the fanzine Farmerphile Issue No. 2, October 2005 were the first 450 words published of an unfinished story, "Who Stole Stonehenge?". People were invited to complete the story, based on this and a five page outline. Alas, no one took the challenge.
See series: Ralph Von Wau Wau

Several sources
 

Farmer had started the third novel in the Opar series, announced as Kwasin of Opar (see above entry, and especially the Opar / Khokarsa entry on this page), but never finished it. The manuscript was redisdovered in 2005 in Farmer's archives, and Christopher Paul Carey got Farmer's permission to finally finish the novel. The title changed to The Song of Kwasin, and it was announced in July 2008 at Farmercon 90 in Peoria.
An excerpt from The Song of Kwasin has been published in Farmerphile Issue No. 13, (July 2008) together with an interview with Chris Carey.
The novel got published in 2012.

Farmer wrote The Stone God Awakens (1970), which was supposed to be part of a trilogy. 

Sources:
- Extrapolation Vol.18. No.1, December 1976
- Amazing, November 1984
 

Farmer in collaboration with Piers Anthony wrote Tappy, a mystery and a love story. The book has been sold to Ace.
This novel has been published as The Caterpillar's Question in 1992 by Ace.

Sources:
- Locus #353, June 1990
- Locus #357, October 1990
 

Two working titles for an all new Tarzan novel. Announced for publication in 1998 by Del Rey.
Published as The Dark Heart of Time (A Tarzan Novel) by Del Rey in 1999.

Sources:
- Locus #443, December 1997
- Locus #446, March 1998
 

A sequel to The Adventure of the Peerless Peer, in which Holmes and Watson encounter a mystery in Ireland. «During which they fall in with Leopold Bloom, whose biography was written by the famous J. Joyce. One of the persons the three encounter is, of course, an Irishman named Finnegan.»

Sources:
- Vector #81, May-June 1977
- Farmerphile Issue No. 12, April 2008
 

See God's Free Beer on this page.
 

See Pearl Diving in Old Peoria on this page.
 

See The Monster on Hold on this page.
 

See The Dragon's Breath on this page.
 

A mainstream novel about the science fiction world. Farmer: "No one has written one yet that came anywhere near doing justice to this wild weird unique phenomenon".
His Balticon 11 Guest of Honor Speech (1977) goes about this idea for the novel. Farmer had the idea to publish the book under the byline of Tom Wode Bellman.

Sources:
- Science Fiction Review #14, August 1975
- Whizzard Vol.2 #10, Fall 1977
- Science Fiction and Fantasy Literature (Vol.2), 1979
- Farmerphile Issue No. 13, July 2008
 

Farmer planned to write sequels to The Wind Whales of Ishmael (1971). They were never written however.

Source:
- Extrapolation Vol.18. No.1, December 1976
 

See The Bronze Serpent on this page.
 

Farmer: "This foreword for this special edition gives me an opportunity to assure the readers that there will be two more books. Seven in all. The sixth will be titled Kickaha's World, and the concluding volume may be titled The Garden of Evil. I haven't made up my mind about this yet, though."
The sixth actually got published under the title More Than Fire (1993), and the seventh book in the series, The Garden of Evil, has never been written, alas.
See series: World of Tiers.

Source:
- "Author's Foreword" to The Lavalite World (Phantasia Press, 1983)