A group of kids photograph zombie Marcy at an abandoned Lake Washington shipyard and then Liv and Ravi investigate in episode 1x03 "The Exterminator".
Mick and Amaya ambush one of Al Capone's deliveries and hijack the truck in episode 2x08 "The Chicago Way".
Source: Brad Toth — Twitter
Webb throws away his suit and decides to head back into the past in episode 1x07 "Weaponized Soul".
Source: What's Filming
The Baudelaire children arrive at a strange mill and are forced to take up jobs in episode 1x07 "The Miserable Mill: Part One". Klaus begins to act strangely and cause problems at the mill in episode 1x08 "The Miserable Mill: Part Two".
Source: Lindsay B — Twitter, What's Filming — Twitter