Introduction: A Newcomer level move for QuickStep.
Frame: Standard. Count: SQQS (DW)
Leaders and Followers: The exact same moves and timing.

Instructions (Leader Perspective)
Going back to the metaphor of quickstep being railroad tracks, the purpose of lockstep is to step onto a third rail (healthcare, taxes, you name it. :D).
Seriously though, this move is basically extending time, so instead of doing a quarter turn, you do one lockstep before doing a quarter turn. Instructions below with the assumption that you are coming off of a quickquick.

Slow0 (technically not part of lockstep, but illustrated here so the move makes sense): Left leg steps forward, heel-toe, you are DW (45 degrees to line of dance). This is just like what you normally do in quickstep.
Slow1: Right leg steps forward, outside the right leg of the follower. Heel-toe as well, this has not deviated from normal quickstep.
Quickquick: Normally, you would step parallel to line of dance, on your toes. But instead, your left leg steps forward. Your right leg comes up behind it, with the right knee locking behind into the left knee. As this point, you are still on your toes. Maintain your balance!
Slow2: Left leg steps forward, toe-heel.
Slow3: Right leg steps forward, heel-toe. This move is the beginning of a quarter turn.

Upper Body: In quarter turn, we ask that you keep your torso parallel to line of dance, while your nose and toes face DW, the direction you're walking down. The reason becomes apparent here. To signal a lockstep, you point your torso in the direction you're walking (NOTE: This may be incorrect. Ask a veteran!). The other thing when signaling a lockstep is to just keep on moving forward.

Instructions (Follower Perspective)
Same as the leader, but you're going backwards. Which means that your front leg will lock to your back leg. That's about it.
Also, pay very close attention to when the leader signals a lockstep. Since you should be following the leader, there shouldn't be any problem when the leader decides to keep on moving forward instead of going to the side with a quickquick.

Tips and Tricks
  • Railroad Tracks 2.0. Now, you have three rails! Your two original rails, and one additional rail. When doing lockstep, the middle rail is where you do your quickquick going DW to line of dance and once again, in between the rails, you're doing slow steps.
  • Tempo. Like the rest of quickstep, make sure to practice at a slow tempo. It is very easy to get caught up in the speed and lose control of your footing, balance, etc.

Advanced Concepts
  • Timing: It's tempting to just rush into the Lockstep, but place as much time as you can on the slows before moving onto the quicks. That way, you emphasize the tempo difference and the sharpness in your moves.