Mr. Lahey is the Darach!
Call me crazy but I think Mr. Leery (Lahey) is the Darach!
In 3×06 ‘Motel California‘, the tally of guest suicides rose by only 3 when there were 4 werewolves at the motel all going through hallucinations so all just as likely to be driven to suicide. Ethan tried to saw himself in half, Boyd tried to drown himself, Scott tried to set himself on fire and Isaac – well Isaac just went a little crazy. There were whispers in the room when Isaac imagined hearing his father’s voice so he was on the Darach’s radar, but he wasn’t driven to attempted suicide – maybe it took longer for him – or maybe the Darach was in Isaac’s presence for another reason…
Isaac could unwillingly be helping his father commit murders, Mr. Lahey can’t physically set foot in our realm (or only in certain places where the currents are strongest) and he somehow possesses Isaac to do his bidding – for example, strangling Harris?
In Motel California we saw Boyd listen to the recording and repeat what he said during the interview – he didn’t say the lines of the other person involved – Isaac on the other hand, said both his lines and his father’s which made me think he either has multiple personalities (I’ve been watching a lot of Criminal Minds lately) – at one point, Isaac even spoke in the tone of his father. It’s either this, or his dad is influencing him in some way, getting inside his head.
This could maybe also explain how the Darach came to work with Harris, Mr. Lahey worked at the school too, maybe they bonded over being mean.
You may be asking yourselves “but why would Mr. Lahey do all of this?!” and I’ll tell you why. Because he’s eeeeeeevil!
It’s been about 6-7 months since Mr Lahey died, this might not seem like a long while, but time could work differently wherever he was sent (a bit like Hell in Supernatural). This could partly explain why the writers showed Derek throwing the glass at Isaac, not only to get Isaac out of his loft, but to also subtly remind us about Isaac’s father!
If time does work differently where Mr. Lahey ended up after he was killed, maybe he found religion in the deepest, darkest depths of hell, called himself a druid, and went on his merry way to create havoc on the world.
I’m probably wrong but I’m getting it out there. Good day.