Exactly eight months, three weeks, and four days after he seemingly vanished off the face of the earth, John Winchester just as abruptly returned. He didn’t bother to call beforehand, he just showed up bright and early at the AC and headed straight for his office, intending to surprise his boys.

You totally know from that sentence that he's the one who's going to be surprised, lol.

And I keep thinking about what John might find when he goes looking for Sam. :D