at the mercy of

1. Also, at someone's mercy . Subject to the power of, helpless against, as in The captured rebels were at the mercy of the army commander . [Late 1500s]

2. Without any protection against, as in On top of Mount Washington we were at the mercy of the elements . [Late 1600s]

Example Sentences

He is at the mercy of such routines until his area gets proper storm drains and levees.

From BBC

"As a farmer, you're always at the mercy of weather," says Harpal Dagar who has a farm on the outskirts of Delhi.

From BBC

But on this trek he had lost his pack and was at the mercy of the elements ever since, hungry, dehydrated and shivering under a bed of needles.

From Los Angeles Times

The arrest underscores how the very political identity he built his business on has now put him at the mercy of the immigration policies he publicly celebrated.

From Salon

How did this happen – and what remedies do customers really have when left at the mercy of rogue traders?

From BBC