Betty learned her shocking fate on last night's 'Mad Men'

With only two episode left of AMC's "Mad Men," many were expecting something substantial to happen on Sunday night's episode to get us ready for the show's finale next week, and fans weren't disappointed.

One of the storylines on the show last night was that Betty Draper has been diagnosed with lung cancer. We hear the news while the doctor talks to Betty's husband, Henry Francis (Christopher Stanley), that it is terminal and that she has less than a year to live, unless she begins treatment which may extend her life for another year.

Back to school taking psychology classes, Betty was walking up the stairs in one of the buildings on campus, looking a little tired, when she lost her footing and embarrassingly slipped and fell on the stairs. At the doctor's office, she learned she has a broken rib, but they also found a tumor spreading rapidly.

Michael Yarish/AMC/"Mad Men"Henry goes to Sally (Kiernan Shipka) at her school to tell her the news - though Betty asked him not to tell the kids - and bring her home in hopes she will convince Betty to reconsider her decision.

Michael Yarish/AMC/"Mad Men"But Betty doesn't concede. Telling Sally that she saw her mother die in a similar way and won't allow Sally and the other kids see her go through that. Also stating that, "she is not a quitter."

She gives Sally an envelope that holds all the necessary arrangements following her death.

Fans of actress January Jones were especially moved Sunday night, and they began sending their condolences to her Instagram account in which Jones posted a picture of Betty in last night's episode. 

Needless to say, some folks who didn't watch yet were not happy receiving the spoiler.