Greenwich, London, 15th February 1894.

Luna thinks that an evening at her aunt's butterfly club sounds deathly boring.

But it turns out that the meeting, held in the Butterfly Room at the Greenwich Observatory, is not at all as Luna expects. The Butterfly Club is a society with an unusual secret . . . they use time travel to plunder the future for wonders.

Together with her friends, Konstantin and Aidan, and a clockwork cuckoo, Luna boards the Time Train. The gang travel to 1912 and find themselves aboard a great ship travelling from Southampton to New York. They locate a man called Guglielmo Marconi and his new invention: the wireless radio. But as the ship heads into icy waters, they discover its name:

The RMS TITANIC

Can Luna and the boys save Marconi and his invention from the doomed ship?

Can they get the radio back home to the Butterfly Club?

And how will their actions change the rest of time?