Box cutters

Things are going from bad to worse for Nick on "Grimm," which returns for its fifth season. The detective (David Giuntoli) discovers his mom's head in a box, which is slightly more disgusting than discovering dental floss in your trick-or-treat bag. 8 p.m. Friday, KARE, Ch. 11

Friday night live

"Best Week Ever With Neil Patrick Harris" may be getting all the attention, but a much better experiment with live television is going on over at "Undateable," a once so-so sitcom that is reveling in its walk on the high wire with lots of inside jokes, audience participation and cast members trying to bust each other up. Make a date with this now compelling comedy. 7 p.m. Friday, KARE, Ch. 11

The cackling dead

"Ash vs. Evil Dead," the latest resurrection of Sam Raimi's indestructible franchise, finds our hero (Bruce Campbell) wielding his chain saw against a new wave of zombies he accidentally conjures up after a drunken one-night stand. The endless stream of blood would be terrifying if it wasn't mixed with a toxic dose of gallows humor. 8 p.m. Saturday, Starz

Explorers club

Can we assume Peter Berg took science classes when he attended Macalester College? He pays tribute to those scrambling to stop potential plagues in the opening episode of "Breakthrough," a new series about scientific explorers. Future installments will be directed by Ron Howard, Angela Bassett and Paul Giamatti. 8 p.m. Sunday, National Geographic Channel

Neal Justin