Go to the start in the dark and using a flashlight follow the reflective tacks. 1 tack means the trail to follow is straight-ish to the next one.
2 tacks means the trail is turning. 3 tacks means someone is messing with you because I only put 2 tacks at most on a tree. 
Continue until you get to a spot where you will see 5 tacks all fairly close to you and to each other; the final is between these tacks somewhere. Have fun and be safe.