Well, what can I say? I like the idea of it, but the structure and dialogue need work.
As for the structure...even in a short...I need to feel something for the character, understand who/what he is at the beginning. It's almost there, with your descripton of his car. Cardboard boxes and medieval books. The cardboard boxes are typically an indication of someone on the outs...just been fired, just been kicked out of his house. Homeless, jobless, hopeless.
Why is he coming home at this moment. Is he happy, rested, tired, anxious, exhausted. Is it a completely normal day. I don't get the context of the situation.
I like the idea that he is going to steal something from the museum to pay the debt, but could you take us through that process? Consider this...
Danielle thinks he's a loser, treats him like a loser, he feels like a loser. (Except in the world of his Medieval Books.) Danielle forces him to go back to the museum to steal gold coins to give to the thugs. But, when he walks by the armour display, he sees the suit (of steel) and decides to take matters into his own hands.
Also, don't they have some pretty awesome killing devices? Halbards, claymores, spikes? Imagine if he took an axe to the front door of the thugs house.
And for the dialogue, much of it is expositional. Specifically, when Kyle says:
"You’re retired and I’ve worked in
the same museum for the last four
decades. The only thing we’ve got
of any value is this house."
They would both know this and would not say it out directly. With enough description of the physical space, there is no reason for them to say they don't have the money...we would already see it.
This is probably a pretty good punch in the gut about the script. I do not mean to knock the wind from you. Keep at it and good luck.