This is part of a collective, consecutive, fast set of A Series of Errands for Lucky.
Mission: Surprise the lazy daytime dockmaster in his place of work and motivate him (deliver a verbal threat) or leave a note in locked drawer
Find the dockmasters station and sneak in (Stealth DC 17 or Lockpick DC 12 & Stealth DC 12)
Perception DC 15 check to observe the shifts and normal movements = Advantage on checks
Threaten him with Lucky’s warning (Intimidation DC 13)
Sneak out without being seen (Stealth DC 13)
Reward: 50 silvers + expenses and a night on him (prostitutes, drugs, booze)