Logic dictates that you wouldn’t take the suspicion of the family nutcase over the word of its respected patriarch, a medical doctor.

Logic wouldn’t lead you to the TV series Blood, which spends six episodes contemplating precisely that decision.   

Blood, a six-part Irish series that becomes available in the States Monday on the streaming service Acorn, revolves around two exceptionally well-played lead characters.

Carolina Main (top) plays Cat Hogan, a lost soul, and semi-vagabond who has been estranged from the rest of the family for years before she returns home to join them in mourning the death of her mother Mary (Ingrid Craigie).

Adrian Dunbar (top) plays Jim Hogan, Cat’s father and the friendly family doctor in their small Irish village. He’s accepting condolences for Mary’s death, which apparently was a terrible accident, and consoling their other two grown children, Fiona (Grainne Keenan) and Michael (Diarmuid Noyes, right).

Mary had been suffering from a degenerative disease that was gradually sapping her strength and coordination. Jim was now doing things like getting her dressed and bathing her. Then one day she was found by the small pond in the backyard, apparently having fallen out of her wheelchair and smashed her head.

Cat, whose presence is barely tolerated by Fiona and who is cut some slack by the more sympathetic Michael, doesn’t endear herself to the grieving family by finding little reasons to doubt her father’s story about how Mary died.

Since Cat isn’t even a pretend detective, she also has no skill at pursuing her doubts with any discretion. Blood is saturated with moments of tension and awkwardness as the family tries to keep Cat in check. Actually, they’re trying to keep her quiet. That’s just not happening, even with the help of Jim’s loyal work scheduler Sarah (Shereen Martin, left).

We viewers don’t know the story, either, which is a smart move in a psychological thriller. But we do see that Cat, for all her thrashing about, isn’t simply a madwoman who needs to be figuratively sedated.

Dunbar plays Jim Hogan exactly as we might imagine. He’s smoothly confident in most of his conversations, particularly with Cat, and tense in more private moments. He keeps us guessing whether that tension stems from guilt over Mary or frustration with Cat.  

Main, meanwhile, gives Cat a long leash. She drinks too much, she’s impulsive, she can’t even park her car straight. She also seems to think more about herself than about anyone else, including the late mother she genuinely loved.

We learn as the show goes along that Cat’s estrangement was triggered by an incident with Jim, which gives her suspicion of his current situation an added edge. It also gives the rest of the family more reason to think she’s just gone crazy again.

Blood fills some of its six episodes with other village subplots, which flesh out the characters but remain secondary to the show’s fairly straightforward central thread. What really happened?

While the answer won’t come as a total shock, it will seem fitting for both Jim and Cat.