When Cyd and Shelby are having trouble studying for a difficult history test, they decide to jump ahead in time and nab the test questions. Meanwhile, Barry and Naldo find themselves in a hair-raising situation when they try to figure out how to make Barry’s invention replicate time travel.

When Cyd tries to plan a special thank you for the Marcus family, Shelby steps in to help with hulu dancers, a rock band and jugglers and everything somehow leads to a big misunderstanding and a huge kitchen disaster.

Cyd and Shelby travel back to relive one of their favorite memories from middle school, but the moment winds up being totally different than what they both remembered. Now, they begin to question everything that happened on that particular day.

When Cyd and Shelby attempt to change the past so that Barry can meet his childhood science hero, they travel to a period where Naldo and Barry are rock musicians instead of scientists.

When the girls travel back to the 70's for help on a report, they land right in the middle of a turf battle between punk and disco kids.

Cyd and Shelby discover a major clue to the future lab memory and it is somehow tied to Barry's Science mentor Janet Smythe, who also employs Shelby's dad.

When the girls discover inventor and GDD CEO Janet Smythe is behind the future lab, they decide to fight back and travel to the past to stop Janet from starting the corporation. Their plan seems to work until they realize they also stopped other major events from happening in their lives, including them living together and Barry and Marci falling for each other.

Things spin out of control when Cyd travels back to Christmas the year before to try and figure out the perfect gift for Shelby. Meanwhile, Barry and Naldo's Winter Wonderland experiment sparks an elf war with Bret and Chet leading the charge.

Cyd and Shelby use time travel to attend two different events on the same night; the plan backfires when they meet boys at both events.

When Shelby's adventurous Grandma Rita comes to visit, the girls learn time travelers were responsible for setting up Shelby's grandparents and they jump to the 1950s to investigate.

Diesel swallows a time travel tracker and disappears; Shelby and Cyd hurry to track him down before he's lost forever.

When Janet unexpectedly invites herself over to Shelby's for dinner, the girls use the opportunity to find out what she knows about time travel.

While Janet tries to uncover the secret behind time travel, the girls decide they need to take her down once and for all!