A mutant, later known as X23, infiltrates the S.H.I.E.L.D. headquarters to gather information about Wolverine and makes a quick getaway.

At the mansion, the new recruits are engaged in a training session, but they don’t seem to comprehend the idea of teamwork yet as Logan makes them start over again. Seeing as it’s Logan’s turn to be in-charge of the training sessions, Rogue insists on staying in the medlab even though she has fully recovered. In the meantime, S.H.I.E.L.D. arrives to seek Logan’s aid in investigating the break in of S.H.I.E.L.D.. The students are overjoyed that Logan has to leave the Institute for the day.

Investigation has led to believe some sort of clone of Logan broke into S.H.I.E.L.D.. A former scientist of Hydra has agreed to help in the investigation. She tells them about X23, designed to be the perfect weapon, modelled after Wolverine, aka Weapon X, right down to his healing factor and trademark adamantium-laced bones and claws. Unfortunately, they could not control her.

Meanwhile, X23 has found her way to the Institute. Seeing the students having fun around friends only fuels her anger as she had grown up without any emotional attachment. X23 watches on as Scott and Jean have too much fun washing the dishes. Scott slacks off to admire his reflection in a plate and Jean seizes the chance to telekinetically redirect the flow of water from the tap into his face. The couple run off, leaving the rest of the dishes unwashed.

X23 infiltrates the mansion, paralysing everyone she encounters on her way with a tiny electronic gadget she attaches to their forehead. In Jean’s room, she takes extra notice of a framed photo of Scott and Jean, recognizing them as the couple she had seen earlier.

Scott, Ray and Rogue are the only ones who managed to evade X23. Logan returns to the Institute and regroups with the survivors of the attack. Eventually, X23 takes out Scott, Ray and Rogue. She fights Logan one on one, siting him as the source of her troubles. Logan refuses to strike back at her. He manages to talk her into stopping. Logan also covers up her escape when S.H.I.E.L.D. comes to apprehend her.

The next day, Logan decides to give the students a break during his training session after realizing that “you gotta let kids just be kids”.