Pilot illness question

[Self Loading Freight]

Hi, all.

I'm writing a short story where one member of a two person flightdeck crew on a bog standard passenger a/c is incapacitated halfway over the Atlantic. I'm interested in what happens when you find yourself alone up front with at least two hours to go before the nearest landing. If there's another commercial pilot without the appropriate type rating deadheading on the flight, what can they do to help?

The story doesn't revolve around the details of the flying, and I'm assuming that the a/c behaves itself, but I'd like to get the protocols right.

Thanks in advance,

R