The Higgs boson was finally found at the LHC, good news you might think? However, its measured mass suggests that our universe may not be entirely stable! It all hinges on properties of the vacuum. I will discuss how cosmology gives us clues about the vacuum that particle physics is challenged to answer. Then I will briefly outline some of my recent research showing how small relic black holes from the early universe can be catastrophic if our Higgs vacuum is truly not entirely stable.