Possible Damaged Wiring
The first thing to do is trip the circuit breaker, pull the out the outlet in outlet 5, and see if it has a good connection and is wired properly. If it's not, fix the installation propblem, turn the power back on, and see if everything works. It should, if you found some problem. It's also possible (although not likely) that the outlet itself failed, so replacing it and seeing if that does the trick might not be a bad idea.
If the outlet seems to be fine, you know it's the wiring that's the problem. You can attempt to pull a replacement wire along the path that the damaged wire ran, although that may not be possible as wiring should be secured close to each box (which may not be accessable) or secured somewhere in between. If you can manage to loosen the staples holding down the wire and pull a replacement wire, well, that's great and after you hook enerything up you should be good to go. Some minor destruction of the drywall will probably be required to do this.
If you can't pull a new wire and can tolerate this option, running a surface conduit between the two outlets can be done, although I hate this option. Those surface conduits can be pretty ugly. Run a conduit between the two outlets and leave the suspect wire in place, disconnected. If I were in this boat, I'd settle for pulling all the drywall between the outlets and running a new wire and replacing the drywall, making sure to secure the wire as required by NEC and installing any metal plates over where wire passes through studs so drywall screws won't damage the wire.
Hope this helps.
[This message has been edited by TchrMommy (edited March 08, 2003).]