An astronaut wounded by a meteorite accidentally brings a brood of insects back to Earth. NASA investigator Dr. Home and entomologist Dr. Bailey have 24 hours to find a better way to get rid of them than nuclear bombardment.

A space shuttle crew return to Earth, bringing alien "seeds" with them. These begin to grow into alien life-forms, needing hosts to complete their evolution... When their number reach the Threshold amount, they will be an unstoppable swarm, so it's up to two scientists to stop them beofre it's too late.—Smish

While repairing a spacecraft, an astronaut is perforated in the arm by a tiny meteor. Once back in Houston, he stays in the hospital for a further examination. Along the night, he breeds some sort of alien moths that attack people with B-negative blood type, transforming them in creatures with claws. Dr. Jerome 'Geronimo' Horne and Dr. Savannah Bailey have forty-eight hours for finding a way of destroying the aliens, otherwise Houston will be completely bombed to limit the outbreak.—Claudio Carvalho, Rio de Janeiro, Brazil