Steel entrapment
rogue attack 23
Requirement: wielding a crossbow, a light thrown weapon, or a sling.
Target: each enemy in blast you can see
Attack: Dexterity vs. Fortitude
Hit: "3[W] + Dexterity modifier damage, and the target is immobilized until the end of your next turn."[PH:125]
Steel entrapment is an encounter power available to rogues at 23th level.