Tempus Fugit Praeterh?c

Based on the amusing idea on the US cover of Deathly Hallows. Harry's Horcrux hunt leads him to Rome. However, he hadn't expected the sudden trip back through time thanks to a booby-trapped Diadem, Neither had Severus Snape, who gets dragged into the backlash of the spell. Now they're both stuck in the past, what are they going to do? Together they struggle to earn a living and have to learn to survive, whilst continuing to search for a way home.