This Is Us Season 6 Episode 13 deals with the passage of time and the advancement of Rebecca's dementia.

As everyone is getting ready for Kate and Philip's wedding, Rebecca says she can't wait for Jack to get here. Miguel stops Randall from saying anything. Later, Rebecca mistakes Kevin for Jack and gets upset when Randall tells her Jack has been gone a while. Miguel tells Randall that the doctors have advised them to go along with it when Rebecca suffers from this type of delusion.

Later, Rebecca again mistakes Kevin for Jack and Kevin takes her for a walk, while Miguel takes Randall wine tasting. Randall wants to talk about Rebecca's deterioration and his concerns about Miguel's health as well. Miguel doesn't want to and angrily tells Randall he needed a break from everything because it's all moving so fast now.

Meanwhile, Beth and Madison discover a note in Kevin's room and realize he slept with a woman last night.They're determined to discover her identity.

And in the past, Rebecca is embarrassed about her spontaneous new haircut, especially after the kids make fun of it.

To find out what happens, watch This Is Us Season 6 Episode 13 online.