Black Trump found the Wild Cards series in a strange place. For the first time since its inception, the series was about to find itself without a regular publisher. To give some perspective, before Black Trump, the series has been running continuously since 1987. After Black Trump, it would be seven more years before another book in the series was published. As a result, the end of the Card Sharks series had the unenviable task of serving both as a coda to the ongoing series while keeping enough plot threads open so that Wild Cards could be resumed again in the future. Because of this the books in the series, this one is difficult to discuss without SPOILERS so expect them ahead.
The book itself pick up where the last one left off: The organization know as the Card Sharks has possession of three vials of the titular Black Trump, a lethal virus that targets people with the Wild Card virus. Senator Greg Hartmann (written by Stephen Leigh), trapped in the deformed body of a Joker at the end of the previous book, sets off with sympathetic human Hannah Davis to find the vials before they can be used. Unfortunately, Hartmans' own Wild Cards powers are beginning to return and with them his evil alter ego, Puppetman, who has plans of his own for the pandemic. Hot on his trail is the Ace government agent Billy Ray aka Carnifex (written be John Jos. Miller) who has been sent to bring in Hartmann for questioning by a government more concerned with covering up the existence of the Black Trump than stopping it. Meanwhile, private detective Jay "Poppinjay" Ackroyd (written by George R.R. Martin) sets out on his own quest to find and destroy the vials while Mark Meadows, the transforming Ace know as Captain Trips (written by Victor Milan) is kidnapped by the Card Sharks and forced to use his biochemistry knowledge to help them perfect the Black Trump. Finally, young Ace Zoe Harris (written by Sage Walker) is forcibly recruited by the Joker terrorists know as the Twisted Fists to steal a nuclear bomb in a last-ditch attempt to threaten the Card Sharks with mutually assured destruction.
As an ending to the Card Sharks triad, Black Trump largely works. The major story arcs are wrapped up; everything is tied up more or less in a neat bow at the end. There are a few structural complaints: It's pretty clear that there were conflicting visions on the final fate of the Card Shark's leader, Dr. Pan Rudo. As a result, a new antagonist, Dr. Carter Jarnavon is unceremoniously introduced for the first time, primarily so that Poppinjay can have a mad scientist to face off in a long set-piece that call back to the very first Wild Cards story while Rudo was occupied in other plotlines.
Stephen Leigh's Gregg Hartman story is a strong third place with several unsettling sequences. Puppetman is a character whose escapades has always bordered on horror, and when he gets loose, it is suitably terrifying. Unfortunately, the story is framed as a redemption story for Hartman and, by this point, he's done too many terrible things even without his maniacal other self for that to really ring true. Furthermore, he spends too much time giving into Puppetman to make his final stand against his "darker side" seem authentic. Still, Leigh is a skilled enough writer that these flaws, while glaring, do not ruin the entire story.
While Carnifex's plotline is serviceable, the real weak link here is Zoe Harris. It's pretty clear that there were at least tentative plans to have the character evolve from the wannabe hero shown in the last book to the next major Wild Cards villain. The problem is that the character is simply not sympathetic enough that the change comes as a major shock. (In all fairness, some of things Harris does were forgivable for a protagonist in the 90s but absolutely do not fly in 2022). Furthermore, Harris simply doesn't make a credible villain. Compared to established antagonists like the Astronomer and Demise, her Wild Card abilities aren't that impressive and she lacks the resources of an organization like the Card Sharks. It's not really surprising that this storyline was abandoned and the character all but disappears from the books after this point.
The end of the Card Sharks trilogy is --- good enough. It works largely as a wrap-up to major storylines and as a pause point for the series. Unfortunately, whether it was from the struggles with the publisher or just that the series had been ongoing for so long, there was a sense that the writers were running out of steam. Even though not everything is resolved, and future book are set up, Black Trump really does seem like a stopping point, like even the writers weren't sure where to go next. It would take two more books before the series found its new direction.
Addendum: The British Ace organization, the Order of the Silver Helix, is introduced. We meet their leader Captain Flint, who will get his own story years down the line. Captain Trips ends the story having apparently permanently transformed into his Radical persona, who is now behaving erratically, which will be a big part of the later books. Gary Bushorn, the "Burning Man", who has a story in the next book makes a cameo appearance as pilot who helps fly Gregg Hartman into Ireland.
