100k House Lien, Unfairly Given To My Parents

Hey everybody, im fairly new/ have low knowledge when it comes to finance & housing, but my parents are (hopefully, knock on wood) about to finish paying for the mortgage, potentially in a year, after 20 years since first giving the down payment on the house.

Mind you, we live in Canada, quebec, MTL.

My dad, about 17 years ago, signed a contract for a loan for himself and two other buddies of his, all in his name, supposedly, for 40k each, from an institution. He says that they had the proof to go after my dad’s so called friends, but instead the institution went against my dad and put it all on him, taking “the easy route” since my dad was the one signing all of the docs. So now that were supposed to realistically have paid them 40k, we now owe over 100k. There was a suit against my dad, and well my dad didnt attend court. My dad also mentioned to me that they’re pretend mafia. Im not sure what that means. Honestly, i’d really just love to see some documents/proof/details on this whole case, and apperantly everytime my moms asked the notary or a realtor they only had a paper with just the amount owed from the lien and thats it. Nothing more than that.

Now before you immediately turn this post down because you think my dad did something dumb and its his loss, ya i agree but i’d like to help turn things around for my parents. My mom wants to bring this to a lawyer and take action now that were more stable, and well i also grew up so ill kick my dads ass if he decides he doesnt want to showup somewhere lol. And he listens to me. I am not financially independent right now but at least i have that power to do good for my family.

My main question would be, where could i get the proof/details for this lien? (To look into it, and see if it’d be worth bringing this to a lawyer)

I would hate it if i needed to get it from the institution where my dad signed it. Especially if they turned out to be somewhat shady.

Secondly, any advice on how to combat this would be appreciated.

P.S. be kind im just trying to get any possible info/advice possible other than the obvious one, which would be to pay 100k+, even if its not our debt to pay. I dont know where to even start. I am a 24y/o waitress/barmaid and dont know a thing about finances and housing, only some general ideas.