supporting cast of Spider-Man's other titles rarely appeared in Marvel Team-Up. The series often featured non-superhero characters in the co-star slot. A multi-issue time travel story arc began in issue #41 with Spider-Man and the Scarlet Witch traveling to the Salem witch trials in 1692, and pushed the barriers of continuity by having Spider-Man team up with two characters who had no established connection to the mainstream Marvel Universe, Killraven and Deathlok. Though the series did often team Spider-Man with other highly popular characters, it regularly gave the co-star slot to obscure characters that the average reader was unlikely to even recognize, particularly during writer J. M. DeMatteis's run. DeMatteis recounted, "I was always attracted to the more obscure characters, mainly because they were ripe for exploration. You could crack them open and really develop them. ... I just looked at these fringe characters as more inviting than the mainstream, more established characters - who all had their set-in-stone continuity. I wanted room to play and those characters gave me all the room I wanted. And let's face it, our lead character was as mainstream as you can get, so the obscure ones made for a nice contrast." With issue #47, the series had a crossover with Marvel Two-in-One #17, which featured the Thing. Jean DeWolff was introduced as a supporting character in the Spider-Man/Iron Man story in issue #48. John Byrne, who would later become the artist on The Uncanny X-Men, first drew the characters in Marvel Team-Up #53. Byrne and his Uncanny X-Men collaborator, writer Chris Claremont worked together on several issues of Marvel Team-Up. Captain Britain, a character created for Marvel UK, made his first appearance in an American comic book in Marvel Team-Up #65 (January 1978). Karma, a character that later joined the New Mutants, was created by Claremont and artist Frank Miller in #100's lead story. A photo cover by Eliot R. Brown was used for the Spider-Man/Captain America team-up in issue #128. Though published for well over a decade, the series format never truly caught on with readers. Upon taking a serious look at sales figures for Marvel Team-Up, Marvel's editorial staff found that sales dramatically rose or fell with each issue depending solely on the popularity of that issue's co-star. Taking this into consideration, Marvel editor-in-chief Jim Shooter concluded that it would make more sense to have another Spider-Man solo series with guest