Line 17

And that very night, as we lay packed tight in our robes beneath the snow,

• Now, the scene switches to that night.
• Service does a really good job of making us feel like we’re there, and he includes all kinds of fun details about life in the Yukon. When they go to sleep, they pack in together under the snow, to insulate themselves from the cold. Sound like fun?

Line 18

And the dogs were fed, and the stars o'erhead were dancing heel and toe,

• This scene at least sounds kind of peaceful, even with the cold.
• There’s something relaxing about this camping moment, with the dogs all fed and the stars "dancing overhead." Things seem kind of calm and normal, at least for the moment.

Lines 19-20

He turned to me, and "Cap," says he, "I'll cash in this trip, I guess;
And if I do, I'm asking that you won't refuse my last request."

• Then, all of a sudden, things take a little bit of a turn. Sam turns to the speaker, and admits that he thinks he’s going to "cash in" on this trip – and he's not talking about finding gold.
• Basically, Sam knows he’s going to die, and he wants to ask for one last favor before he dies. Jeez, how could you say no to that?
• Oh, also notice that he calls the speaker "Cap." We don’t know how much we can read into that, but maybe it means that the speaker is a captain, or the leader of the expedition. We also kind of get that feeling from the way the speaker talks, but it’s really just a hunch.