Herpes simplex virus (HSV) infections last a lifetime. Once a person has been infected, the virus can remain dormant (latent) for years before periodically reactivating to cause recurrent disease. This poorly understood cycle has frustrated scientists for years. Now, scientists have identified a set of protein complexes that are recruited to viral genes and stimulate both initial infection and reactivation from latency. Environmental stresses known to regulate these proteins also induce reactivation.