Fill in the blank: If the king's avarice gets out of control, he might decide to ...

Upon making inferences based on the given incomplete sentence, a possible sentence would be:

If the king's avarice gets out of control, he might decide to collect more taxes from his people.

The key word in this sentence is 'avarice'. It means an extreme greed for wealth or an insatiable desire for wealth. Thus, if the king's avarice gets out of control, he will find ways to gain more money although through unjust ways.