As we see in the promo, there are scenes from Snow Falls in it (charming cutting down snow) and we also know Abigail is back. Along with the fact the Emma & Hook go into the past, I wondering if this is the point we return too. I think the "Snow Drifts" might refer to snow changing her mind about charming, after Emma & Hook do something. Like instead of snow "Falling" for him she "Drifts" away?