-- It was a week that threw us off balance, like a punch-drunk fighter facing blow after blow.

It began with a terrorist bombing. Ricin-laced letters. A horrific fertilizer plant explosion that devastated a town and left untold dead.

Then, from Thursday into Friday, the frenzied manhunt  for the Boston bombers -- complete with a grainy photo, a cop killing, a  stolen car, gunfights, thrown explosives and wild chases through the  darkness -- left one suspect dead and effectively shut down the city.

As high noon came and  went on Friday, literally thousands of law enforcement officers gathered  on the streets, many going house to house in search of the remaining  suspect. And then, Friday night, the man was caught and the nightmare,  apparently, over.

It was so exhausting, so  intense and so preposterous that one could only hold on for dear, dear  life and wonder when -- if? -- the whole dizzying ride would end.

As the Onion headlined a story: "Jesus, This Week."

The satirical online  magazine quoted "Maryland resident James Alderman," "Seriously, can we  wrap this up already? Because, you know, I'm pretty sure we've all had  our hearts ripped out of our chests and stomped on enough times for one  seven-day period, thank you very much."

What else can you say? Other events -- the gun legislation shot down by Congress, the Midwestern storms that flooded Chicago, the Venezuelan election, the discovery of possible life-supporting planets, a 7.0-magnitude earthquake that hit China's southwest Sichuan Province -- became mere blips.

It's as if the shock of  bombs shattering the joy and grace of the Boston Marathon set off more  than just an explosion. They set off nerves and fears and tempers, some  ancient chaos deep within our souls.

Off balance

For most of us, weeks  have predictable rhythms: the ebb and flow of work or school, the  weekend errands, the breaks for worship or recreation.

Not this week.

Lost in the powerful  pulse of tragedy after tragedy, it's only human to long for the  predictable. We look for patterns, and we start seeing them where none  exist. Was the Boston bombing linked to the Texas explosion? Were the  ricin letters connected to the arguments over gun legislation?

Were they all of a piece?

Randomness, points out  San Diego-based psychiatrist Dr. David Reiss, goes against the human  grain. What we want is certainty. When that goes away, we connect the  dots with another glue: anxiety.

"What connects it all is  the fear and the sense that life is so uncertain, and no matter what we  do we can't totally protect ourselves," he says.

In fact, it's an accident of civilization that we group time in terms of "weeks" -- that is, a seven-day period.

The ancient Romans had an eight-day week until the early years of the empire. The French Revolutionary Calendar adopted a 10-day week to go along with its 10-hour days and 100-minute hours. The Soviet Union had five- and six-day weeks during the 1930s.

The seven-day week, though deeply ingrained, is an invention of ancient Jews, Mesopotamians and other civilizations who divided the monthly lunar cycle into fourths.

But today we look at days as boxes on a calendar, and a week as a line of those boxes. And this particular line was jagged.

Bill Iffrig's finish

Anxiety is closely  related to memory. In the case of the past week, one couldn't help but  think of the 9/11 terror attacks, which literally came to us out of a  clear blue sky. After 9/11 came the anthrax scare, a plane crash in New York City and the Washington sniper shootings. In retrospect, we know that the events weren't connected, but at the time, rumors ran rampant and anxiety rose higher.

The same was true this  week. The mishaps of the media, the gossip ricocheting through the  Internet, the perpetual "on"-ness of our 24/7 world -- no wonder the  week sometimes felt out of control.

"(The pace) doesn't  allow for processing," says Reiss. "Even if you go into a very mild,  nonclinical post-traumatic state, it still takes a day or two to get  back to normal, and you don't have a day or two because something else  has come up."

We can take solace from  history. One can point to many moments in time in which it seemed like  apocalypse was just around the corner. The world often seems like its "centre cannot hold" -- that it's going to end, until it doesn't.

When we look back, this week may be seen as the beginning of something -- or, more likely, an outlier.

More heartening is the  way people pull together. After the Marathon bombing, the world  expressed solidarity with the people of Boston. (Even the New York Yankees paid tribute.)  After the Texas explosion, there were immediate outpourings of sympathy  and charity. Much divides us, but sometimes a little chaos can bind us  together.

At the very least, chaos may bring out our resilience.

Perhaps the most appropriate symbol of that is Bill Iffrig, the 78-year-old runner who was knocked down by the force of Monday's blasts and then got up, determined, and walked to the finish line.

The bomb was quite a shock, he says, but when he took stock of himself, he felt OK. So why not cross the finish line?

"I ended up second in my division," he told The (Everett, Washington) Daily Herald. "After you've run 26 miles you're not going to stop there."

Life is a marathon, not a sprint.