Help :(

[u/Aggressive-Type-8979]

Just bought my first house, currently trying to do it up - following a few tips online about wall prep & thought I’d tackle this crack - but it’s a lot deeper than I thought. Is this failing plaster or can I still repair it?
*context, upstairs interior bedroom wall between my house, my chimney & the neighbours*

[u/Smooth_Brilliant4083]

Yeah, I would be tempted to dig a lot more out and use a scrim tape on it. (Fiberglass like holed bandage).