I'm getting there... I'm getting there... up to #11!
This is the one where the Baudelaire orphans end up on a submarine with Captain Widdershins, whose motto is 'He who hesitates is lost,' and his stepdaughter, Fiona, who realizes that sometimes hesitating might be the wise thing to do - but who may not be trustworthy.
Not only do the three orphans have to escape the clutches of the evil Count Olaf, here they must also avoid dying from exposure to poisonous fungus, the Medusoid Mycelium.