Carolina Birmingham was a caregiver for her ill father, but upon his death she applies for the job to become a Pinkerton agent after seeing an advertisement in the paper. She has always dreamed of being one and now she has her chance.

Ned Lewis doesn't think much about training a woman agent. He doesn't even mind the marriage part as long as the female agent is able to pull her weight.

When the circus comes to town, the two have to find an assassin who is using the circus as a cover for murder. With Ned's efficient skills at finding a needle in a haystack and Carolina's many disguises, will they find out who the assassin is in time to save the infamous Priscilla Marlowe from an assassin's bullet?

As they say, The show must go on, but who will pull the final curtain - the assassin or the Pinketons?