Tillie the Dog had been missing for a week when volunteers found her safeguarding her trapped best friend—another canine named Phoebe. According to BuzzFeed News, Vashon Island Pet Protectors (VIPP) posted a frantic status on September 12 asking for help in finding the furry companions. It wasn’t until that following Monday when a concerned member of the community reported a possible sighting, saying a “reddish” dog matching Tillie’s description had wandered onto their property before racing back to a nearby ravine.

The tip paid off and volunteers quickly found them. However, they were surprised at what they saw. Tillie stood at the edge of the reservoir dutifully watching over her trapped friend. VIPP recalled the discovery in a detailed Facebook post:

So with a needle in the haystack hope we made our way into the ravine and after a bit of searching, finally heard that sweet sound we have been waiting for all week. A small one-woof response when we called out “Tillie.” A few minutes later we found her laying beside an old cistern with her head resting on the concrete wall. Heart sinking…we knew that meant Phoebe was inside the cistern and every breath was held and every doggie prayer offered that the peek over the rim would somehow find her safe.

And gratefully… this time we have a happy ending with dear Phoebe found perched on some concrete rubble that held her out of the water. For nearly a week Tillie stayed by her side with the exception of the few minutes of each day when she went for help.

Both dogs were reportedly cold and hungry, but otherwise fine. They have since been reunited with their owners. Thankful to see their safe return, Amy Carey of VIPP had some advice for owners whose pets may have gone missing.  “If you have a lost pet and are not getting regular sighting reports, there is a high chance that they are stuck somewhere be it over a slope, in a building, or in this case in a cistern,” she told BuzzFeed News. “And a reminder that when trying to find a missing dog, you need to pay attention to even the smallest clues.”