Episode Overview
Title: Missing Link Plot: While on a mission in The Carthage Region, the Scyphozoa ambushes Yumi, capturing her human DNA and leaving her stranded in Lyoko. To complicate matters, it's picture day at school, and her absence could lead to suspension. Ulrich devises a plan to have Sissi fill in for Yumi, and surprisingly, she agrees without asking for anything in return. Meanwhile, Jeremie works on a solution to rescue Yumi. Aelita hatches a plan but keeps it secret from Jeremie until she's in Lyoko. She intends to transfer her genetic code to Yumi, risking Xana’s control over her memories. Fortunately, Odd and Ulrich arrive just in time to intervene, while Jeremie discovers that Yumi's DNA might be retrievable from Xana's memory in Sector Five.