Tom Oakley experiences disturbing episodes of deja-vu and believes he is going mad. Then, he discovers that he's a "Walker" - someone who can transport himself to other times and places. Tom dreams about other "Walkers" in moments of mortal danger: Edward Dyson killed in a battle in 1879; Mary Brown who perished in the Great Fire of London; and Charlie Hawker, a sailor who drowned on a U-boat in 1943. Agreeing to travel back in time and rescue them, Tom has three dangerous adventures, before returning to the present day. But Tom's troubles have only just begun. He finds that he's drawn the attention of evil individuals who seek to bend history to their will. Soon, Tom's family are obliterated from existence and Tom must make a choice between saving them and saving his entire world. Tomorrow's Guardian is a Young Adult Fantasy Novel."