Why was he carrying two bags? He shouldn't have been, no one carried two bags.
Unless one was a bomb.
The other was his getaway bag; a few clothes, a flashlight, some peanuts. That's what everyone took in their getaway bag.
You follow him onto the train, eyeing his every move in case he intended on leaving the bag behind. You plan your steps, intending to swoop in, catch him before he leaves.
He'd die too at least.
No one would know of your last heroic deed but that's okay, you'd know. When you were dead.
You sit in the seat behind him.
He's fidgeting, a lot, more than any normal person would. More than anyone without a bomb would.
He pulls the bag onto the seat and you lean forward as he takes a look inside.
Your heart is beating. Is this really going to happen? You're prepared to jump.
He takes out his phone.
This is it.
"Hi honey, how's the labour going? That baby better not come out before I get there."
He doesn't have a bomb. Just a baby.
You lean back with relief.
You're life wasn't about to explode.