Nick explains what a prime number is and determines that the serial killer commits a murder on dates in the month that are prime numbers.

The team listens in to communications coming from outer space and notices a pattern: each signal represents a prime number. They determine that the signal is coming from the star, Vega. After recording the sequence, the team displays on the computer screen that every prime number between 2 and 101 has been sent to them.

The captain tells the squadron that he is expanding it to four members, which concerns all of the lieutenants. Lt. Purcell states that four is an unlucky number because it's not prime. He then defines a prime number.

Smilla compares numbers to human life and defines natural numbers, negative numbers, and fractions.

The CyberSquad finds that no one is on floor -3, and Motherboard cannot track their location. Jackie guesses that they are on floor -5, the Grand Ballroom, so Digit tries to determine which direction to go. Initially, he thinks that they should go up, but that turns out to be incorrect. Jackie, Inez, and Matt explain to Digit why -5 is less than -3.