Grief has a way of bringing people together.
Shannen plays the person who tells us what happened to Fred, explains showrunner Roberto Aguirre-Sacasa.
She was there and shes an unexpected source of comfort to Archie.

Robert Falconer/The CW
A big piece of what happened to Fred comes to Archie through Shannens character.
The scene is so heartbreaking because you really feel Shannens love for Luke.
Aguirre-Sacasa admits the days after Perrys death were extremely challenging for the close-knit cast and crew.
Its been really, really intense, says the showrunner.
Luke and Fred were very similar guys.
They were both salt of the earth.
They were both generous and led with their heart.
And it was really hard the days after Luke passed.
That sentiment really resonated and a similar sentiment is expressed in this first episode.
And its really cathartic.