With so much packed into Fallout 4, it would be easy to pick something up and easily dismiss it. However, imgur user 1Times took a closer look at a Flux Sensor that they found in the wasteland, and did a little research after finding a number on the sensor while taking a closer look.

“I found some random numbers (CM-88B 180924609) so I decided to do some research,” 1Times said on imgur. “I found this. It’s a screen capture from the movie Alien.”

ALIEN

After further research, it was discovered that 180924609 is the registration number of the USCSS Nostromo, the spaceship from the horror classic Alien.

“It feels really rewarding,” 1Times wrote. “Encourages me to explore more.” 1Times also posted pictures of where to find the Easter egg, including where it is on the map and its location inside the hut that it was found (seen below).

F4EE F4EE2

This discovery may not be the only one within Fallout 4. Gears of War creator Cliff Bleszinski tweeted that a good friend of his who worked on Fallout 4 said “…there are more numbers hidden in the game.”

Fallout 4 is available now for PC, PlayStation 4, and Xbox One. You can check out Gamespresso’s review of the title here. Fallout 4 shipped 12 million copies worldwide on its first day on shelves.