The serialized TV thriller is alive and well on pay cable. Take Showtime on Sundays, which is serving the finest doubleheader of darkly disturbing drama anywhere on TV this fall. Dexter? So twisted. Brotherhood? So crooked. And this applies as well to HBO’s riveting five-week miniseries Five Days, a missing-person mystery that plays like the most multifaceted Without a Trace episode ever.

If I’m most partial to Dexter, it’s because it feeds my insatiable appetite for the macabre. There’s no other way to describe the appeal of an audacious crime drama whose hero is a serial killer, albeit one who targets only bad guys. (By day, he’s a crime-scene analyst for the Miami police.) Michael C. Hall is sensational as Dexter: outwardly charming, inwardly devoid of emotion — or is he?

In Dexter’s second season, which picks up a month after the finale, his life is spinning out of control and his killer timing is off. “I’m just a little rusty since killing my brother,” he explains. (Long, bizarre story.) He feigns normalcy for his sister, his girlfriend and his coworkers, but Dexter’s mask begins to slip when his watery burying ground is discovered, and an FBI “rock star” (the terrific Keith Carradine) is brought in to expose Miami’s latest serial-killer sensation. Bloody great stuff.

Brotherhood, Showtime’s grittier and less mythic answer to The Sopranos, is more serious than Dexter but no less enthralling in its violent and dynamically acted dissection of politics, crime and family ties in Providence, Rhode Island. Quiet tension seethes throughout this tangled drama’s second season as politician Tommy (Jason Clarke) is rocked by his unhappy wife Eileen’s (Annabeth Gish) infidelity, while his street-thug brother Michael (Jason Isaacs) copes with brain damage and the arrival of loose-cannon cousin Colin (Brian F. O’Byrne) from Ireland. The real showstopper here is Ethan Embry as family friend and conflicted cop Declan, whose downward dive into addiction, despair and guilt is laced with unbearable pathos.

Five Days, an HBO-BBC collaboration airing over five Tuesdays, also goes for the emotional jugular as it immerses us in the anguish of a family trapped in limbo after a young mother suddenly vanishes. As police suspicion and relentless media scrutiny take their toll, a blue-chip cast of British pros (David Oyelowo, Penelope Wilton, Patrick Malahide, Edward Woodward, Janet McTeer) elevate the melodrama. The suspenseful story jumps days or weeks between episodes, each hour focusing on a pivotal day in the investigation. I watched with an escalating sense of dread, but still was unprepared for the powerful twists along the way.

Dexter airs Sundays, 9 pm/ET, and Brotherhood airs Sundays, 10 pm/ET, both on Showtime (also online via video.tvguide.com).

Five Days airs Tuesdays, 8 pm/ET, on HBO.