Kirk and his security team search for the creature. Spock, suspecting it may be a silicon based lifeform, modifies their phasers to be more effective against silicon. They encounter the creature -- which has the appearance of molten rock -- and fire upon it, breaking a piece of it off. The creature flees by burrowing through a rock wall. Spock analyzes the fragment, whose composition resembles fibrous asbestos. He deduces that it burrows through solid rock by secreting the same corrosive substance that has killed the miners. Spock adjusts his tricorder to scan for silicon-based life, and confirms that the creature is the only such lifeform for miles.