The season finale for NBC's hit family drama "This Is Us" comes up on Tuesday night.

One major element of the show's first season success has been its ability to wring a good cry out of viewers almost every week.

Mark Barger explains.

The season finale of "This Is Us" airs at 9 p.m. Tuesday.

The show will return this fall.

And in a relatively rare thing for network television, its' already been renewed for two more seasons.