Data from Richard Bleiler's "The Annotated Index to The Thrill Book".
The October 15, 1919 issue carried an announcement that the magazine would become a monthly with a cover date of December, 1919. The magazine ceased publication with the October 15 issue. "Medusa's Venom", "Gifts of Tsin Lee", "For Art's Sake", "Impulse", and an untitled two-part serial by Francis Stevens were announced for succeeding issues.
"The Gift Wife" (Part 4 of 4), a nongenre story by Rupert Hughes was a Middle Eastern adventure story that was announced for this issue. It was published as a novel in 1910 and is available on the Internet Archive.
In addition, there were a number of stories that were known to be inventoried for future publication in The Thrill Book. Those that might have been genre stories are also listed here.
"As It Is Written" by De Lysle Ferrée Cass was published in 1982 but the author was misattributed as Clark Ashton Smith.
Inventoried stories that were least likely to be genre are:
"In Memory of Sarah Clewett" by Anonymous.
"The Grin of Chang-Hi" by Eric Darling.
"The Evil Men Do" by Edmund Elliot.
"After Fifteen Years", "Love at First Sight", "Their Pasts", and "Was She the Right One" by Marbury L. Thompson.