Frank Castle is Marvel Comics' most lethal hero, so it comes as no surprise that he's done some unseemly things since becoming the Punisher. The preview for The Punisher #7 teases a return to one of Frank's classic arcs, revealing an untold story that has everything to do with the mysterious, scarred old nun Sister Mercy.

The preview starts with Frank getting thrown into jail in Zemo-ruled Bagalia. He meets one of the prison's bosses, Sister Mercy, in short order. As it turns out, Sister Mercy has met Frank before. The final page teases that the nun met the Punisher (or was at least affected by his actions) in the "Jigsaw Puzzle" arc that kicked off in The Punisher #35 in 1987.

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That arc saw the Punisher travel to Venezuela to stop Jigsaw and a demon-worshipping villain named the Rev from harvesting a sterility-inducing plant, which their monstrous master intended to use to purge humanity from the face of the Earth. Apparently, Sister Mercy was a missionary at the time and even met the Rev, witnessing his mystical healing powers in action.

We don't get any more context from the preview, but the Punisher eventually went on to foil the Rev's plans. It seems clear that Sister Mercy was affected by Frank's quest in some way, and that it likely led to the hideous scar she now bears.

The Punisher #7 goes on sale Jan. 30. Matt Rosenberg writes the issue. Szymon Kudranski pens the art. Greg Smallwood provides the issue's cover.