Warning: spoilers from Episode 7 ahead! From the very beginning of the season, Luke's fate on The Handmaid's Tale had appeared to be sealed. June, like us, took the sounds of those gunshots in the woods to mean that the Guardians of Gilead had killed her husband in his attempts to help them escape across the boarder. But we (and Offred) learned at the end of Episode 6 that this was not the case. Luke is still alive. So will Luke rescue Offred on The Handmaid's Tale now that they've established some means of contact? It certainly seems at least somewhat possible.
Episode 7 (aptly titled "The Other Side") showed viewers Luke's side of the story and what he himself has gone through both before and after he and June parted ways. While it's true that he did, in fact, get shot during his confrontation with the Guardians, the wound wasn't a fatal blow. En route to the hospital, the ambulance crashed and left Luke as the only survivor. From there, he tried to make his way back to where his wife and daughter were headed, but found their stuff scattered in the spot they were taken. Luke knew what this meant, but he pushed on until he was discovered by some others who were also looking to escape across the boarder. Many of them were killed before they reached safety. Only Luke and one other survived. They've been living in Little America (known as Toronto, Canada) for the past three years.
The woman Luke has befriended (shown above) was found at one of the Handmaid training camps prior to their escape. She had yet to speak any words to anyone due to the trauma she suffered and it seems like she may still not be speaking even years later. We don't even know her name. It doesn't seem as though Luke knows for sure what June's role now is as a Handmaid, but he did know Gilead was rounding up all fertile women, so he may have some idea of what's involved. Undoubtedly, now that he's been informed that she's still alive, he'll try to do everything he can to rescue her from the nightmare she's currently living in.
The note that he received from her was brief but full of meaning. She said that she loved him, but told him to save their daughter, Hannah. I'm sure he has every intention of following her orders and trying with all his might to track Hannah down. However, I have a feeling he'll try to put the same amount of effort into saving June as well. They clearly love each other very much and this renewed sense of hope should definitely give him the incentive he needs to keep the search up.
Viewers still don't know what's happened to Hannah since she was dragged out of her mother's arms, but I have a feeling she's alive as well. And if that's the case, maybe there is still a chance (however small it may be) that the three of them will be united someday.