Оборот с внутренним артиклем

at a loss - в недоумении, растерявшись

Ilam said nothing. He was naturally at a complete loss (A. Bennett).

E 1 e n a: It wasn't my fault - he died a natural death - several years ago - in Geneva.

H а г г у (at a slight loss): Geneva? (N. Coward).

I heard to-day ... something which I find hard to credit an action of yours which if it is true I am at a total loss to understand (A. Wilson).