As you do. [He's not gonna judge your weird coffee habits.] Well I suggested we get them sick. You know, classic excuse, 'Oh we couldn't make it everyone on the ship has the flu.' Except it needed to be them to avoid suspicion. So we figured out a planet they would be docking at, arrived incognito and through various dastardly plans broke into the local center for infectious disease control, stole some semi-harmless samples and snuck them in the air vents of their ship. With lots of drama and sneaking and blaster fire, obviously.