Simply put, this Sunday marks the In Plain Sight episode that you cannot miss.

It's not due to the witty, pun-laden title of the installment ("Something A-mish"), nor to the unusual circumstances of Marshall and Mary helping an Amish person adjust to life as a witness.

Instead, it's due to a certain piece of shocking news delivered to Mary. With delivered, as this preview teases, being the operative word...

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.