Still far from the strongest Doctor Who story, but the Target novelisation affords Rona Munro some added depth for the Ninth Legion characters. We get more of Kar's backstory, and the Picts and Legion's attempts to guard the portal, which means their decision to step through the portal to keep the titular monster at bay has more impact.

Bill comes across as weirdly confrontational in the way she's described in the text, particularly at the beginning, when challenging the Doctor's views on what happened to the missing Ninth Legion. Overall, however, this story works much  better in prose than it did as a TV episode.