Event One - Introduction: Go to the railroad after 7pm any time after having met the wizard.
Event Two: Requires 2 hearts with Alecto. Go to the Forest map after 8pm.
Event Three: Go into the Witch's Hut for the first time after receiving the magic ink quest from the wizard (this event can trigger before event two).
Event Four: Requires 8 hearts with Alecto, and having seen all previous events. Alecto needs a favour - you will get a letter in the mail telling you what to do...

Bonus Event - NPC Wellwick:  Requires two hearts with both Alecto and Wellwick. Go to the wizard's hut between 6pm and 2am.
Bonus Event - East Scarp: Requires two hearts with Eloise. Go to the deep mountains map between 10am and 6pm on a non-schoolday (Monday, Thursday, Saturday or Sunday)