Hostile takeover on the Red Line

Kayleigh's Red Line commute from Alewife did not get off to a good start this morning:

... Fortunately, I somehow popped in through an door with an empty seat right beside it. Feeling lucky, I inspected the seat for gum, and was turning around to sit when suddenly a woman rushed in UNDERNEATH ME and sat in the seat! She gave me a shove with her arm and hate lasers shot out of eyes. I said something like "Whoa!" and backed away before she could whip out a knife. She continued to stare at me, like a feral animal ready to bite. The odd thing was the train car still had plenty of open seats – including two directly beside the one she'd just pushed me for. ...