After receiving a gushing fan letter, the iCarly gang invites Mandy Valdez, their self-proclaimed biggest fan, to attend a webcast with their first live audience (consisting of Mandy only). Mandy quickly reveals that she's more than simply a fan of the group -- she's obsessed, to the point where she sneaks into Carly's apartment in the middle of the night so she can join Carly and Sam watching TV, sends them pointless gifts and even transfers so she can attend the same junior high as the group. It reaches the point to where Mandy starts to disrupt their broadcasts, in particular while doing her duck impersonation (complete with duck mask).