St Mary's is back and is facing a battle to survive in this, the fourth instalment of the Chronicles. Max and Leon are re-united and looking forward to a peaceful lifetime together. But, sadly, they don't even make it to lunchtime. The action races from 17th century London to Ancient Egypt and from Pompeii to 14th century Southwark as they're pursued up and down the timeline, playing a perilous game of hide and seek until they're finally forced to take refuge at St Mary's – where new dangers await them. As usual, there are plenty of moments of humour, but the final, desperate, Battle of St Mary's is in grim earnest. Overwhelmed and outnumbered and with the building crashing down around them, how can St Mary's possibly survive? So, make sure the tea's good and strong...