When Mary Blake agrees to help an old acquaintance being blackmailed, she never imagined she'd stumble into another murder investigation.

Within 24 hours of her arrival, a suspicious death occurs, plunging the Rudolph Hotel into chaos just before their big Christmas event. With the police dismissing foul play, Mary dives headfirst into the case, joined by her trusty assistant Dot and her eager brother Pea. 

Together, they must track down the killer and prove their worth in their new career as amateur sleuths.