TV - Movies
Star Trek
Storylines That
In both “The Wrath of Khan” and "The Search for Spock," Lt. Saavik seems to be set up to succeed Spock. However in "The Voyage Home," Saavik only has a cameo and gets left behind on Vulcan while the crew returns to Earth and is never referenced in the canon again.
Saavik’s Destiny to Lead
By the end of the “Next Generation” series finale, Deanna and Worf seem to be firmly established as a couple, the result of years of legwork by the storytellers. However, when the characters return for the Generation film series both pursue relationships with other characters, and their romance is never referenced again.
Deanna & Worf Break Up?
At the end of the "Deep Space Nine" episode "Defiant," Thomas Riker is forced to surrender to the Cardassians in order to save his crew, and sentenced to life in a labor camp. Major Kira Nerys, swears to rescue him, but this rescue never comes and this is the last time Thomas is ever mentioned in any canonical "Star Trek" work.
Still Rotting In Prison
At the close of the "Star Trek: Deep Space Nine," Worf accepts an invitation to become the Federation's new ambassador to the Klingon Empire. But later in "Star Trek: Nemesis," Worf has returned to his old post as chief security and tactical officer aboard the USS Enterprise with zero explanation whatsoever.
Worf Demoted?
At the end of the "Equinox" two-part “Voyager” episode, Equinox is destroyed, leaving only five survivors that end up being integrated into the Voyager crew. They are stripped of rank and put under constant surveillance and then they are never seen or spoken of again.
Equinox Crew Disappears