Marvel gave Jack a miniseries in 1984, and it was being created at the time this issue came out. I’m pretty sure that’s why he got a guest shot on MTU.
Not much story here–Jack is basically under home detention by SHIELD, he busts out, and they chase him around. All this issue really does is re-establish the character, expositing that his powers are killing him and his girlfriend Marcy is trying to find a cure, which will be the plot of his limited series.
It’s even “to be continued.”