The storyline ??? (possible spoilers)

Let me see if I got the story straight:

Jack (oldest son) comes home from the war, goes to work for family hotel.
Bad guy (Harrison) arrives at hotel with evil/cursed war medals.
Jack starts acting strange.
Dad kills Mary's boyfriend.
Entire family killed, youngest son disappears.

At some point, a body believed to be Harrisons is found. When was that?

What was the deal with everyone being axed to death except Jack, who was stabbed multiple times with "something small, like a pen knife."

Did Jack ax everyone? Who killed Jack?

Was the bad guy Harrison? Did they find out what happened to the youngest son?

yeah the ending was a little strange, wasn't it? And things were never really explained.

I was hoping to find the answers to these questions in here myself! Absolutely ridiculous - no resolution or explanations to those AT ALL! Sheesh! It's a little insulting actually - like they thought we wouldn't notice.

Please someone figure out this story line. I'm so lost. who was the guy at the end trying to be immortal. and when did immortality ever get mentioned. So lost