For the upcoming Star Trek: Generations (due this fall) Marina Sirtis was delighted to find out that her character, empath Deanna Troi, gets to pilot the Enterprise. But she wasn't thrilled with how the scene played during filming. The sequence began with an on-set explosion, followed by Sirtis sitting down to guide the ship. But ''the explosion left embers on the seat,'' says Sirtis. ''I sat down and it set my bottom on fire. There I was, hopping up and down, going 'Ow! Ow! Ow!''' Fortunately, Sirtis was unharmed, but the accident left some emotional scars. ''On the next take, I went over to the chair, and in what [was supposed to be] a life-or-death situation, I stopped and wiped down the seat,'' says Sirtis. ''It gave [the crew] a good laugh.''