Dava

Dava is the friendship between Ava Jalali and Dylan Walker.

Series
Pilot

Sex, Lies and Alibis

...If One of Them is Dead

The Ghost Sonata

Timeline
First Relationship:
 * Started: 1-year prior to "Pilot"
 * Reason: Nolan formed the Perfectionists and forced them all to be his "fake friends".
 * Ended: Pilot
 * Reason: With Nolan now dead, the group was temporarily disbanded, with Ava wanting nothing to do with Dylan or Caitlin. (102)

Second Relationship:
 * Started: Sex, Lies and Alibis (103)
 * Reason: Ava started to let Dylan in after his kind message offering to talk. Their friendship, however, didn't really begin until "...If One of Them is Dead".