starting issue-hi guys my first time posting over here

ok so i just bought a 2000 volvo s80 t6 its silver bueatiful car with 150 on it but it does not run the previous owner said it ran great then one day he jump started his moms car she started hers and his died when he tried to restart it the alarm went off they let it sit for a coupe of days and when they came back to it and crank it over nothin happened except a ticking noise from under the dash that doesnt stop until you take the key out they did try putting a used battery in it with no difference but the used battery may or may not be good it wont be towed to my house until tommorow afternoon so i havent tried or look at anything just wondering if anyone has experienced anything like this or knows a good volvo mechinic in the catonsville md area thanks for your help

You can buy a new battery, for the cost of the tow truck.
Take batteries in to get a charge & load tested.
Both of them are probably bad!

Make sure battery connectors are clean + tight.