How come they appear in subsequent novels, if they're dead?

His subsequent novels met the same or possibly even greater indifference.

Balance of Power set the tone for his subsequent novels, which feature politics, law and military action.

Subsequent novels in the series ring changes on this basic formula.

However, subsequent novels based on the series have retconned this, saying that the two are still involved with each other.

Nearly all of his subsequent novels were based on detailed historical, cultural, and even geological research.

And a third, based on Galsworthy's subsequent novels about the family, has been planned.

Many of Abé's subsequent novels have also been set in the medieval time period.

In the course of my research for subsequent novels, I would learn to walk into places safe and dangerous and ask anyone questions.

It did not sell well and neither did her subsequent novels.