Just Another Saturday Night was first published in Sin City #1/2 (August 1997), a limited mail-in comic available only through a special offer in Wizard #73. It was later reprinted in a mass-market edition as Just Another Saturday Night (October 1998).
It is the story of what Marv was up to on the night John Hartigan met back up with Nancy (from That Yellow Bastard). Marv regains consciousness on a highway overlooking the Projects, surrounded by dead young guys, unable to remember how he got there. He lights one of the dead guys’ cigarettes and thinks back; since it is Saturday, he deduces he must have been at Kadie’s watching Nancy dance…
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