When Dr. Ernst stands in the center of the ICU, surrounded on all sides by computer terminals and cardiac monitors, he imagines he is on the bridge of the starship Enterprise, a guardian of unknown galaxies. But by 3:00 a.m. the space fantasy has dissipated into the air like so much ether, leaving behind only a profound and desperate desire for sleep. The needs of Ernst's patients are as endless as his round of duty. Their lives are mere blips on the VDT console, their last bids for fading life sound as alarm bells in the night.