Megan Boone Megan Boone

The Blacklist is full of mysteries, and its characters are the most baffling (and intriguing) ones.

When the NBC crime drama returns for its second season this fall, fans once again will delve into the murky identity of master criminal Red (James Spader). And while everyone is obsessed with whether or not he's FBI Agent Liz Keen's (Megan Boone) father, clues may be found in Liz's own character.

Fall TV: Scoop on your favorite returning shows

In this exclusive video, look back at all that we know about Liz Keen — from her trusting nature to her brutal ruthlessness.

What hints are there that she may be related to Red? Or does he have a different, yet equally compelling reason to be interested in her? Share your theories below!

The Blacklist returns on Monday, Sept. 22 at 10/9c on NBC. Catch up on last season's finale here.