Star Trek: Assignment: Earth is a five-issue limited series, written and drawn by John Byrne, based on the events in the Star Trek second-season finale, "Assignment: Earth". The series was published by IDW Publishing. One notable story shows Gary Seven's and Roberta Lincoln's peripheral involvement in the events of a prior Star Trek episode, "Tomorrow Is Yesterday"—which, due to peculiarities of time travel, happens after "Assignment: Earth" for Seven and Roberta, but before "Assignment: Earth" for the Enterprise crew. Source: Wikipedia (en)