What a shame that Zoe comes from the 21st century. Her version of the 21st century seems so much more exciting than that of the real world 21st century. She works on a space station, was educated with advanced learning techniques - what a time to be alive. But then there's the "Hourly Telepress", and the comic book exploits of the great, the powerful, The Karkus.
It's a wonder how the Karkus ever had a following, really. The first of two appearances by Christopher Robbie in Doctor Who (and his second appearance seven years hence goes just as well), his Karkus is the weakest part of and otherwise excellent story thus far, although most of the blame has to be placed upon the fight scene that the Karkus and Zoe have soon after the cartoon superhero is introduced. In a perfect world, this would have been shot on film and had the benefit of editing. As it was recorded in the studio, we see Zoe holding her arms out in anticipation of the Karkus's punches, the Karkus doing flips on his own, independent of Zoe's efforts, and Wendy Padbury completely fluffing her line at the end of the scene.
The final shot of the episode, however, redeems any shortcomings that this episode might have, with the brilliant visual of Jamie and Zoe getting trapped in between the pages of a giant book. It's another in a long line of literal visualizations of the perils that The Doctor, Jamie, and Zoe are experiencing (such as "Jamie is safe and well" and "when is a door not a door? When it's a jar" from earlier episodes). Jamie and Zoe are about to be trapped in fiction just as they're about to be trapped in a book. Superb stuff.