It's a few weeks before the wedding. In their continuing slap bet, Marshall wants the next slap he exacts on Barney to be the most painful thing that Barney has ever experienced. Marshall knows however that this threat means nothing to Barney as Barney is now immune to Marshall's constant taunting. Marshall, as such, proceeds to tell Barney a story of the extensive training he got from the masters of slaps to achieve his goal, that three part training which includes how to exact slaps of a combination of speed, strength and accuracy. Marshall not only has to convince Barney that he went through this training, but to convince Barney enough that Barney is once again traumatized by Marshall's constant taunting. Written by Huggo