Q-Squared
Peter David
 Trelane, who first appeared in the original Star Trek episode "The Squire of Gothos", is revealed to be a member of the Q Continuum. He taps into the power of the continuum and uses this ability to tamper with time and reality, resulting in the intersection of three different parallel universes which are also referred to as time "tracks." Track A is a universe in which Beverly Crusher's husband Jack never died, and now serves as captain of the Enterprise with Jean-Luc Picard as his first officer; in this universe, Jack's son Wesley died as a boy and Jack and Beverly divorced. Track B is the traditional universe depicted on Star Trek: The Next Generation. Track C is akin to the more militaristic alternate universe shown in the Next Generation episode "Yesterday's Enterprise", in which the Federation is at war with the Klingons. Q, who had been charged with the task of "mentoring" Trelane (a task each "adult" Q must accept at least once for an "adolescent" Q), enlists the aid of Picard and the crew of the Enterprise-D in the three different timelines in order to teach Trelane discipline, and eventually, to stop him from destroying the fabric of the universe by collapsing the alternate universes together. When the tracks begin to merge, the characters from separate universes begin to appear to one another, sometimes with disastrous results. Jack Crusher confronts his ex-wife about the affair she is having with Track-A Picard; during the argument, which Track-B Picard witnesses, she is accidentally killed; additionally, members of Track C attempt to kill Worf, and believe all the members of the crew from the other two universes are really Klingon impostors. Eventually, Q manages to overpower Trelane and the universes are once again separated, though not always perfectly (at the end of the novel, Track-A Data appears to be stuck in Track C). Q also spends part of the novel lost in time and space, trapped by the barrier around the galaxy; this relates to the original series episode "Where No Man Has Gone Before".