In our last session, Hjalmarr's ally, Brother Ike, was torn to shreds (to past -10xHP) by a Ravening Eye aka Eye Beast, one of the known eye monsters of Felltower.*
How does this affect Hjalmarr, and why?
Hjalmarr had 8 points invested in Brother Ike - he was an always appearing NPC on 50% of his point total.
Those points are gone. Ike is dead beyond Resurrection and the PCs have no access to the kind of magic (for example, a wish) that would be able to bring him back or make him subject to Resurrection.
But wait, doesn't the Basic Set (p. B37) say, "If your Ally dies through no fault of yours, your GM will not penalize you. You may put the points spent on the deceased Ally toward a new Ally"?
Yes, yes it does.
But I feel like losing the points here is warranted.
First, is taking your ally in a megadungeon, leaving him in the back rank, and making some poor organizational and scouting decisions followed by poor tactical decisions "no fault of yours"?
I'm going to go with no. It sounds like a lot of the reason Ike is eyeburger is because of Hjalmarr.
Second, I feel like death in the course of normal adventuring is a reasonable way to lose points. You can permanently lose a limb, gain a disadvantage, pick up a new quirk (or many), get cursed, etc. So if you can lose points in this way, why not when your Ally gets eaten?
Third, if getting your Ally killed with bad choices and bad luck means you get the points back, why not risk your ally freely? It's essentially a way to cost-free swap one out. Don't deliberately get it killed, but put it where it gets killed, then pick a new and different one with a spell loadout/advantage list/whatever that suits you. It's actually a risk-free way to get a lot of points.
Speaking of which, fourth, Ally is a large power multiplier for the points you put in it. What you get for 4 or 8 character points is worth a lot more - 125+ points - than a +1 or +2 to a skill, +2 or +4 HP, not even +1 ST, etc. If that means you get more than you put in and normal misadventure or bad playing just means you get them back again or get another Ally, I think that's an unreasonable extra benefit.
Finally, some allies are deliberately set up to be disposable. I think it cheapens the upsides of them if non-disposable allies are effectively just persistent, not permanent.
Now, I know this isn't the RAW - and DF5 even allows for keeping the points if you deliberately get an Ally killed - but I think it suits the "GURPS DF on hard mode" style of my game.
* Along with the Eye of Death, Sphere of Madness, and rumored others!