steal of home, strike 3

[newump]

R3, 2 outs. 0-2 count on batter. R3 steals home. slides in safely before the pitch crosses the plate for strike 3. does the run count?

does it matter when R3 took off for home?

i believe that if a runner steals a base and slides in safely to another base before a pitch is fouled off the runner must return because he had not reached the following base at the time of pitch. does this theory hold true in my scenerio? since R3 had not reached home at the time of the pitch is his run nullified?? or it is simply a time play? and since he crossed home before the ball crossed the plate - then run counts.

any rule citations would be appreciated. any differences between levels?? thanks