Nor do many people understand that a secret once lost is a secret no longer.

The fact that Trumpet wasn't empty might not remain secret much longer.

If someone hears you sing, the song is no longer secret.

I vowed that, come what might, it should be a secret no longer.

The fact that we are no longer secret should put an end to most of those fears.

It cannot remain a secret much longer, in any case.

Well, we were a secret no longer, but the Insectoids would still have to find us.

When the plot is ripe it remains no longer secret.

That will change somewhat now that your presence is no longer secret.

The secret ace, he thought, might not be secret much longer.