I like to binge read sequels to H. G. Wells' "The Time Machine" whenever I can. I thought that I would post a list of some of the novels I found that purport to be what happened next, after the time traveler disappeared. Have you found any that I missed?
"Timeslip Troopers" by Théo Varlet.
"The Return of The Time Machine"* by Egon Friedell.
"The Hartford Manuscript" by Richard Cowper.
"The Space Machine" by Christopher Priest.
"Morlock Night" by K. W. Jeter.
"Time Machine II" by George Pal.
"The Man Who Loved Morlocks" by David J. Lake.
"The Truth About Weena" by David J. Lake.
"The Time Ships" by Stephen Baxter (only sequel approved by Wells estate.)
"On The Surface" by Bobert J. Sawyer.
"Beyond The Time Machine" by Burt Libe.
"Tangles In Time" by Burt Libe.
"The Time Machine: A Sequel" by David Haden.
"The British Empire: Psychic Battalions Against The Morlocks" by Simon Baxter.
"Epilogue: The Time Machine Chronicles" by Jaime V. Batista.
"Time-Machine Troopers" by Hal Colebatch.
"The Time Traveler's Tale: Chronicle of a Morlock Captivity" by Paul D. Schullery.
"Nebogipfel At The End Of Time" by Richard A. Lupoff.