If you are looking for outrageous climbs this trail is not the place. There's not any insane downhill nor any bomber drops, horrendous rock gardens nor any technical ledges. Nope, none of that nonsense.
Twilight Zone is a great XC ride through the desert with moderate climbs & descents through and around the rolling hills and washes off Hwy. 157 going to Mt. Charleston.
Follow the trail that drops off the NW side of the parking area that flows around the foothills in front of you. At one point you'll cross a cairned intersection. Left or straight both take you CW around the trail, right will take you CCW. This gps track goes straight.
As you round the north side of the trail you encounter a watering hole off-trail to your right, a good place to take a break and scout around. From there follow the trail east as you round the mountain then south. At the cairned intersection turn left retracing the trail you rode in on.
The temps here tend to be @ 10 degrees cooler than Cottonwood or Bootleg, so this can be a small reprieve from Vegas temps.