The stocking-stuffer reprinted the third and fourth issues of the short-lived US comic (the first two adapted the movie and reached the UK in the form of this IPC special) which took the crew through the black hole and into an alternate dimension with mirror-images of themselves and Maximillian and his boss. At the time this all seemed amazingly cool but - today - not so much.
The page count was padded-out by some nice behind-the-scenes features, with colour pics, on the making of the film.
The original US comics are pretty hard to find. Publisher Whitman pulled their line from traditional distribution streams (and the growing number of specialist stores) in favour of multi-issue bags sold via mass market retailers. However, according to contemporary accounts (in fanzines like THE COMIC READER) the results were hit-and-miss with distribution extremely patchy.
The disappointing box office, combined with Whitman's problems, killed the comic after the fourth issue.