S0

S0 (season zero) refers to the events that take place before the first season. The events of S0 are only really shown through flashbacks and references by the various characters. The duration of SO is roughly a month.

Hillary and Volt are in a Relationship
Hillary may have done this to piss Gauge off

Gauge gets gang bashed by Volts crew
Idk why. Reed and Gauge are almost always together, except for this occasion. Reed was hanging out with Ruth. Because of this, Reed gives Ruth the cold shoulder from now on.

Hillary dumps Volt
After hearing of what happened to Gaige, Hillary ends her relationship with Volt. (This event may or may not happen in S!).