Holtzmann's First Weapon is the first weapon Jillian Holtzmann ever tested, with explosive results.
A teenage Holtzmann decided to use St. Paul's Chapel as the site to conduct her first weapons test despite others urging her not to.  She chose the night of Friday the 13th.  Holtzmann managed to push her hefty weapon and its cart upstairs into a room. She started the weapon but something went wrong. She ran for it and yelled out for anyone to run for their lives. Abby Yates, Erin Gilbert, Patty Tolan, and Holtzmann fled to the cemetery and hid behind headstones. The chapel partially exploded. They noticed each other and ran away in opposite directions. In the end, Holtzmann learned so much and felt the incident was worth it in the end. They each buried the memory of the incident and only realized they previously met each other over a year after they became Ghostbusters. Holtzmann had a common memory between the four of them to perfect her Dream Machine and defeat Doctor Kruger.
- On page 15 of Ghostbusters: Answer The Call Issue #4, Holtzmann echoes Dr. Frankenstein's "It's alive!" line after she turns on the weapon.
- Ghostbusters: Answer The Call
- Jillian Holtzmann (2018). IDW Comics- "Ghostbusters: Answer The Call Issue #4" (2018) (Comic p.10). Jillian Holtzmann says: "You know, this is just like the first weapons test I ever conducted."
- Patty Tolan (2018). IDW Comics- "Ghostbusters: Answer The Call Issue #4" (2018) (Comic p.11). Patty Tolan says: "This was Friday the 13th, right?"