At this point it’s a local tradition: “We play a costume party in Eugene every year,” says Miss Alex White of the Chicago-based rock ‘n’ roll brother-sister duo White Mystery. “White Mystery loves the people of Eugene, its punk-rock spirit and great food.” White Mystery also loves Halloween: “Halloween,” White jokes, “means White Mystery Airheads, group costumes and my half birthday.”

This year, local music promoters, fun-mavens and friends of the band Behavior Castle are bringing White Mystery to town for a free all-ages show Halloween night at The Barn Light. Along with drummer “Francis Scott Key White,” White Mystery is touring in support of 2014’s Dubble Dragon, a collection of stony, noisey, junky and punky classic rock tunes blending ’70s stadium rock like Thin Lizzy with the stink of cheap beer, ripped jeans and black leather jackets.

While the track “Komodo Silverback” is a hallucinogenic noise assault, album opener “Dubble Dragon” is a White Stripes-esque garage-rock scorcher. “Follow Me, White Rabbit” is a trippy 13-minute epic that rides along on a George Thorogood-style roadhouse-blues riff.

So would White Mystery prefer a trick or a treat from Eugene this Halloween? “This remains to be seen!” White says.

Behavior Castle presents White Mystery plus “tricks, treats, costumes and drink specials,” alongside live DJs playing “lots of spooky records,” 7 pm Friday, Oct. 31, at The Barn Light; $5 in costume, $8 without; 21-plus after 10 pm.