"Rock Around the Clock" is the one-hundred and fourth episode overall and the twenty-fifth episode of the fourth season in Wizards of Waverly Place.
The current landlord of the Russo's building decides to sell the sub shop, evicting the Russos of the shop, as well as their apartment and lair, which contains their portal. Without the portal, the Russos will lose all contact with the Wizard world. So, the entire family (along with Harper) travel back to 1957 to stop Jerry's father (the previous owner of the shop) from selling the shop to the landlord, so that they do not get evicted. Jerry's father agrees not to sell the shop, and the Russos return to present day. However, they accidentally leave Harper behind when Harper is distracted by a woman with a poodle, and Harper suggests that the woman should put a picture of a poodle on her skirt, creating a poodle skirt, which were popular in the 1950s.
Back in present day, the Russos (who have not yet realized Harper's absence) find the sub shop obsolete, boarded up, and empty, with the subway car and the lair missing, too. The Russos realized that they have messed with the fabric of time, and something they did while time-traveling in 1957 must have created a ripple effect, and affected present day.
While Alex suggests that they go back to 1957 to find out what they did wrong, Justin denies this, saying they should not solve the problem by doing exactly what caused the problem, however Theresa states that they will have to go back, when she realizes that they left Harper in 1957. The Russos return to 1957, where Jerry's father reveals that he did not sell the restaurant to the landlord, however the restaurant failed to make enough business, and that he has been forced to close it. Justin realizes that when Jerry's father lost the restaurant, he moved out of the building and since their family no longer lived in the building, the lair disappeared in present day. The Russos decide just to find Harper and go back to present day, and discover that Harper enrolled at Tribeca Prep as soon as they forgot her in 1957, as Harper did not want to ruin her perfect attendance record. Justin, Alex, and Max go to Tribeca Prep to retrieve Harper, while Jerry and Theresa wait at the sub shop, however Harper decides to stay in the past, as she finds new popularity in 1957 that she does not experience in present day. While at Tribeca, Max introduces the high-five to several students. Alex realizes that if they make the sub shop the 1957 high school hangout, the sub shop will get better business and will not have to close. However, no one has any fun at the sub shop that night as the jukebox is broken. Just as everyone is about to leave, Max plugs his MP3 player into the jukebox and Harper uses her popularity to get the students dancing and having fun at the shop, and the business at the sub shop peaks. The Russos return to the present day, where the lair and the sub shop are back, and Jerry owns the entire building, while the landlord is now the owner of a Janitor service, instead of the building, and the high-five is now called a "Max". Alex then remembers that they forgot Harper back in 1957 and they go back and get her. (the Russos accidentally end up in 1977 twice in the episode, thanks to Justin)
- John DeLuca as Tommy and Jeff Sizemore as Lenny Hune Jr.
- Brendan Bradley as Hank Russo and Carlo Michael Mancini as Lenny Hune
- Since the episode aired out of production order (its production code preceding "Wizards vs. Asteroid") there is a chronological error when Harper mentions she has been allowed to stay in the basement till graduation (as both she and Alex had graduated on Wizards vs. Asteroid). For that same reason, Harper would not have to re-enroll at Tribeca Prep since she most likely graduated with a perfect attendance record.