This is the first book in the time hunter series. It was originally published in 2003 and based on characters from a doctor who novella, the cabinet of light. When telos lost the rights to publish doctor who books they created the time hunter series featuring the two characters fom the original doctor who novella, Emily Blandish and Honorè Lechasseur. (Eighteen years later telos have reprinted the eleven time hunter novellas and as a bonus have presented an alternative cabinet of light as book zero, making twelve time hunter books.)
I enjoyed this novella. It's very well written and establishes the premise of the series well. The story is good and the characters well drawn. I didn't read these at the time they were originally released and decided to read them after seeing they had been reprinted. Very enjoyable book.