What resolves first: Sacrifice draw or Deathknell from the sacrificed unit?

Sacrifice kills as cost, so Deathknell finalizes on top of Sacrifice. On resolution you resolve Deathknell first, then Sacrifice. Baited Hook kills on resolution — Deathknell pending, Hook continues, then pending items finalize in order: Deathknell, then the Hooked unit and its When You Play Me trigger.