roll in phrasal verb ( see also ↑ roll )
1 . to happen or arrive in large numbers or quantities:
As the result of our appeal, the money came rolling in.
2 . to arrive, especially later than usual or expected:
Chris finally rolled in at about 4:00 am.
3 . if mist, clouds etc roll in, they begin to cover an area of the sky or land:
Fog rolled in from the sea.