In many ways, it was the most serious problem of all.

Then came the last and the most serious of questions.

It was the most serious look I have ever seen on anyone's face.

I have seen such cases before, and they are most serious.

She was also the most serious baby I had ever seen.

But it certainly wasn't the most serious thing in the world.

Or perhaps answer only the most serious ones and let the others go.

Allow me to point out the two most serious of these.

We are being called upon to deal with a most serious matter.

I had to be looking at the most serious man I'd ever met.