What makes this book stand out from the crowd, at least in its more engaging first half? It is not the time-travel premise; that has been done to death. Neither is it the plot, which has children chasing the device which will return them home. That, too, is hardly a novelty. The appeal of this story is the characters: Kate, Peter and their families in the present; morally ambiguous Gideon and his enemies, and the more straightforward Byng family in the past.

There is a direct if unspoken contrast between twelve year old Peter's family life, in a well-to-do suburb of London, and Kate's in a Derbyshire valley. He is an only child with a mother who, while not formally separated, is certainly absent. His father, well-meaning but busy, breaks a promise to celebrate his son's birthday and leaves him with the au pair. Which brings us to Kate's family: a family of six children, a scientist father and a housewife mother. Lastly, in the past, we meet the Byngs, an 18th century family with several children who offers Peter and Kate an open welcome when they find they have traveled back in time. The author makes no particular comment on the disparity between the families. When the children disappear, Kate's parents are bewildered, while Peter's feel guilty. When his mother hears that he has disappeared, she comes straight back, effectively losing her job.

The Byng's employee Gideon makes a far more interesting character than the conventional guide-to-the-past which one finds in such stories. He was taken as an urchin under the wing of the rich Lord Luxon and became the nobleman's conscience and tame thief. He eventually escaped, but remains embroiled in Luxon's schemes despite his own wishes. He is full of admiration for the description Peter gives of the 21st century, although it is a shame that Peter's viewpoint extends no further than the technological and material advances of the two hundred years which separate them. Certainly, the author paints no golden picture of the past. The food is unpalatable and personal hygiene is slight. Kate has to wear uncomfortable clothes, and robbery and injustice are rife. But the children bear up with courage and resilience.

Tim Golden is a computer programmer living in London.  He is also the editor of the Good-to-Read website.