Spatch answers the question that vexed inbound commuters at Davis Square this morning: How the hell did trains keep heading outbound to Alewife when only one train came from Alewife this morning?

... The real explanation is that there is a freak rift in the time-space continuum in the train tunnel and it is centered directly underneath the northbound tracks. Trains travelling northbound don't actually reach Alewife, you see, for they fall through the rift and end up in the lair of an ancient Eldritch horror so arcane and powerful that the mere sight of its full name will cause any mere mortal being's head to explode. ...