Whoa, baby! When a neighbor hires Nancy, Bess, and George to take care of her eighteen-month-old identical twins, the girls are happy to help. After all, the Clue Crew has stopped would-be thieves, uncovered scams, and recovered stolen objects -- how hard can watching a couple of babies be? But being a mother's helper is trickier than they thought, especially when the twins' toys start disappearing. Can the Clue Crew look after the babies and figure out who's taking the toys, or are they in too far over their heads this time?

It's time for the Holiday Streetwalk in River Heights. That's when the stores serve cider and cookies, carolers sing on street corners, and there's face painting, clowns, and costumes for everyone to enjoy. But the best part is when the mayor turns on the Christmas tree lights and Mr. and Mrs. Claus arrive in a horse-drawn sleigh.One lucky child will get to present Mr. and Mrs. Claus with the key to River Heights, and this year it's Bess Marvin! There will be reporters and TV cameras on the big day, but Bess's chance to be a star is ruined when the key to the city disappears. Can Nancy, Bess, and George unlock the secret of the missing key before Bess's special day is spoiled?

Part of the re-launch of the popular "Nancy Drew" series, this story finds Nancy hot on the trail of poachers in Yellowstone National Park. Her boyfriend Ned has been studying the marmot population and calls for Nancy when he discovers someone is stealing the prized animals for profit.