[s1e19] - Compass

: The story reveals Mac’s past at MIT, including the fact that he was enrolled at age 17 and had a major crush on Frankie. Further Story Development

: To help Frankie process DNA samples while on the run, Mac creates a DIY centrifuge using common items like a bicycle wheel or salad spinner—noted as one of the best "hacks" in the series. [S1E19] Compass

: Frankie’s DNA research could be linked to future "Phoenix Foundation" cold case files or Mac's own family history. : The story reveals Mac’s past at MIT,

: Jack breaks his arm in a trash compactor at the beginning of the episode. This occurs because Mac tells him to hold a pipe "perfectly normal" (a physics term meaning perpendicular), which Jack misunderstands. : Jack breaks his arm in a trash

: Mac creates an electric whip from a cut extension cord to defend the team against the gunmen pursuing Frankie.

: Developing the "hurt/comfort" aspect of Jack dealing with his injury while still trying to protect Mac. "MacGyver" Compass (TV Episode 2017) - IMDb

After hearing that Frankie died in a lab fire, Mac travels to MIT with , who is on mandatory medical leave with a broken arm. Their investigative instincts kick in when they notice a suspicious man at the memorial and learn that Frankie's supervisor also recently died in a mysterious car crash.