Build a mask that tells us who you are. That’s the challenge John Keasler posed to the men in his fellowship group on their weekend retreat last April. Keasler, 58, an HIV positive AIDS educator in San Diego, slapped on his own: images pulled straight from the pages of POZ. “Masks are tools of discovery,” he told the group, which has positive and negative members. “When hidden behind a mask, we’re often more frank in our sharing.” A brilliant disguise.