It's two years later and the Pharaoh has an unsettling dream. He dreams that seven "sleek and fat" cows emerge out of the Nile and are eaten by seven other "gaunt and thin" cows (Gen 41:2-3). Gross. Joseph has built up a reputation as a dream interpreter (kind of new age-y for the Bible, methinks) and is called in to give his expert opinion. He says that the people in Egypt and surrounding areas can expect seven years of abundance followed by seven years of famine. Yeah - I guess that was pretty obvious. The Pharaoh is so pleased with Joseph's interpretation that he gives him a cool new nickname: Zaphenathpaneah. Just rolls off the tongue, doesn't it?
The Pharaoh decides to pass the buck to Joseph and make him in charge of storing grain and meting it out when the famine hits. It does and eventually Joseph's shitty brothers show up looking to buy some. They don't recognize him so he decides to pull a bit of a power trip. He holds one of them hostage (Simeon) and tells them he won't let him go until they return with their youngest brother (himself). However, he gives them all the grain they want for free. Mixed messages.
I don't really know what Joseph expects to get out of this scenario. Maybe he just wants them to realize that he's their brother and he's still alive. Why not just tell them? After all, he's much better off than they are: grain guy, dream interpreter, and pal to the Pharaoh. Even if you've been treated badly by someone, it always feels pretty great to run into them after you've got an awesome new job or lost a bunch of weight or got extensions or something. If your life is decidedly better than that someone's, it's easy to say, "Oh, it's all water under the bridge".
Anyway, the brothers scramble home wondering what the hell to do. Reuben, the only one who ever spoke up on Joseph's behalf, makes a bizarre promise to their father, Israel: "Slay my two sons if I do not bring him back to you; put him in my hands, and I will bring him back to you" (Gen 42:37). Quite drastic, I think, and a tad sitcom-y, too. It seems to set up a completely unnecessary conflict.