Is it possible for household wiring to go dead mid-wire with no sign of damage?

I have an 80 amp wire hardwired from a gang-breaker to my hot tub pump with no junction boxes or anything along the way. The breakers are on and the wire has juice according to my electricity tester for most of the way and then (of course) about 5 feet shy of the hot tub, the wire suddenly goes dead with no sign of damage to the vinyl sheath that coats it. I've never heard of a wire doing this and I'm wondering if this is common and if anyone has any ideas of how to fix it shy of pulling an entirely new wire. I would prefer not to have to splice a new end on with a junction box if possible (because that just opens up a whole new invite for long term issues) but I would equally prefer not to have to pull a new wire given the distance to the breaker is about 80 feet through a maze of floor joists and other obstacles hidden behind mostly drywalled ceiling. Is there an option I am not aware of?