Passage: While exploring space for new habitable worlds, a probe belonging to the bio-engineering corporation Life Foundation discovers a comet covered in symbiotic lifeforms. The probe returns to Earth with four samples, but one escapes and causes the ship to crash in Malaysia. The Life Foundation recovers the other three and transports them to their research facility in San Francisco, where they discover that the symbiotes cannot survive without oxygen-breathing hosts, which often fatally reject the symbiosis. Investigative journalist Eddie Brock reads about these human trials in a classified document in the possession of his fiancée Anne Weying, an attorney preparing a lawsuit defense for the Life Foundation. Brock confronts Life Foundation CEO Carlton Drake about the trials, leading to both Brock and Weying losing their jobs. Consequently, Weying ends their relationship.

Question: How many specimens does the probe come back to Earth with to start?
four