ORIGINAL AIRDATE: May 1st, 1989 ---
Terrorists threaten to shut down an entire city if their demands are not met
MISSION: MacGyver happens across a team of terrorists hijacking a piece of military hardware with which they plan to take an entire city hostage. MacGyver and Pete must go it alone to sabotage the threat.
This week's highlights include:

Electromagnetic pulse (Physics)

An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy. Such a pulse's origination may be a natural occurrence or man-made and can occur as a radiated, electric or magnetic field or a conducted electric current, depending on the source.

Check out the article on wikipedia: https://en.wikipedia.org/wiki/Electromagnetic_pulse.

Watch S4E17: "Easy Target" on CBS's website or check the alternative streamability of this episode here.