Back when I first started writing for a living, it was common to write a new piece, print it out, place it in an envelope, and mail it to my editor. This was especially helpful when missing a deadline, because it was easy to blame the US Postal Service for being late.

That all changed with fax machines, but there was still the handy excuse that the fax machine was out of paper or some such claim.

Then came the "modem," which involved a fax-like transmission and a number of strange commands, all of which could still be seen as a cause for being late, due to the low quality of the technology.

Of course, then came email. It became possible to be speaking with an editor on the phone and sending a document in real time. Within the span of seconds a document could flash from one side of the country to another — or even around the world. Missing a deadline could never again be blamed on anyone but myself.

Which brings me to this moment, as I type this blog with my thumbs while standing along a running track at 6 a.m. while my runners train, moments away from texting it to the web goddess Nikki for posting.

February 24 marked exactly twenty-five years since I began writing full-time. I'd left my corporate job for three weeks to cover an adventure race in Madagascar and got fired my first day back. Despite the impending financial hardships of life without a steady paycheck, I rejoiced. There have been endless ups and downs in the quarter-century since, but I'm still blessed to wake up every day and dip into my routine of coffee and the LA Times before walking precisely thirty steps from the kitchen to my office in the garage. I'd written a few books before framing up the office, which now features bookshelves, air conditioning and heating, and wall to wall carpeting. But I think it was Knockdown back in 1999 or so that marked the first book composed within those walls. Since then, either solo or with a co-author, something like fifteen other books have been written there. It's not like it's a national landmark or anything, but it's nice to know that the Killing series, which has sold more than 15 million books, was researched and roughed out in the space on the other side of the wall from my mountain bike.

Which brings me to another milestone: the end of the Killing series. It's been a decade since Bill O' and I have begun collaborating. The latest is almost finished, and there's a contract for at least once more. But whether the final sentence of the series is written next year or the year after, the bestselling non-fiction series in publishing history must inevitably come to an end.

It's a little scary. I have not written a book of my own in eight years, which is off for someone as independent as myself. I never thought I would be a good collaborator, but it turns out I've now written more books with other people than by myself. When Antarctic explorer Colin O'Brady recently went looking for a co-author, I was happy to put name in. We had a delightful conversation about telling his story on a very tight deadline, but in the end we live in different parts of the country and crashing the book would have been a logistical nightmare.

I think what I'm trying to say is that I can write books standing on my head. It's what I do. Other than coaching distance runners, my skill set is limited to just that. Stepping out to tell my stories, in my voice, however, is suddenly a scary proposition. But it's almost time. The book I really want to write is a first-person take on these last twenty-five years since I left the corporate world. But I fear my agent would throw me out of his office if I approached with something as patently uncommercial as that.

Having said that, why not? Nothing to lose.

We'll see. What I want to write is something great, something capable of standing up to the Killing books, which I absolutely love. So that's the challenge. Twenty-five years ago I began working the high wire without a net. Now it's time — almost — to do it again.