Episode 95 of "Angel"
s05e07 Lineage

When a sting operation is interupted by an assasin cyborg, the Angel squad take it in for examination. However, while back at W&H, Wesley is suprised to see his estranged father, Roger, make a surpise visit - with news of possibly returning him to a reformed Watchers' Council. Despite declining his offer, Wesley's father sticks around while the rest of Angel's team get to work on researching the cyborg assasins, and are shocked to find out they might actually be fighting on the side of good. This brings about a conflict of interests when the assassins infiltrate the W&H headquarters, and at the same time Wesley's father knocks his own son out and steals an artifact from the vault - with the intention of using it to steal Angel's will power and use him as a slave. This culminates with a mexican stand-off between Wesley and his father on the roof of W&H, but all is not as it seems with Roger Wyndham-Pryce.