My sometime co-author and I are celebrating our 42nd wedding anniversary. I know 42 isn't one of the big anniversaries, not ending in 0 or 5, but 42 is still a large number. Our very first co-authored book, Murdering Mothers (about infantide in England and New England from the 16th to 19th centuries), was published when we'd been married less than a dozen years. We wrote it under extreme conditions. Peter was teaching at OSU in Columbus, Ohio; I was in graduate school at Columbia University in New York City. Long distance telephone rates and air fares were prohibitively expensive for an impecunious graduate student and an untenured assistant professor. There were no unlimited calling plans. There was no Skype. Calls and visits were few and far between. There were times, almost frighteningly, I began to forget what Peter looked like. Increasingly, our two lives drifted apart. He was consumed by teaching and campus politics. I was completely absorbed in my graduate studies and caring for our toddler son. Telephone conversations became stilted. We had only two reference points upon which we could connect. The first was that toddler son I mentioned. The other was the book we were trying to write together, what became several years later the aforesaid "Murdering Mothers." Our tenuous relationship, the very survival of our marriage in those early years, hung by those very thin threads. I have often thought that if we hadn't been collaborating on that book during that period apart we would not have been able to sustain the marriage. Nearly four decades later, we still struggle with separations. And the collaborations -- at least five books and counting -- continue to act as the glue keeping our marriage in tact.