Some treacherous elements were in place.

He went to leave, but some nosy treacherous element of his make-up had already slammed the door behind him and faced him up to the room's other occupant.

Folks drown in this treacherous element.

The sea was a treacherous element; a ship but a frail conveyance -fragilis ratis - tossed by the billows at their whim, and subject to every wind that blew.

In fact, just until the end of the harbor, the 'treacherous element' was being very well behaved, and the light pitching of our boat moved us to a charming sort of languor.