That'll Tichu to Mess With Us
A good detective benefits from having a good partner. Sometimes it's due to teamwork and knowing how the partner thinks. Other times, the abilities of the two complement one another, such as when the mostly fearless detective is scared stiff by the sudden appearance of a snake, and his partner reassures him that it's a harmless garter snake.
Have two people learn (if they don't already know it) the rules of the partnership card game Tichu and send them to headquarters to win a hand against expert players. Both people must know the rules and will not be allowed to consult either the rules or with each other during play and if they make illegal plays will be sent away and forced to come back at a later time. Learn the game and then call HQ to set up an appointment to play.