What strange events happen in castle that lennox describe scene 3?

In Scene 3 of Act 1, Lennox describes several strange events that have occurred at the castle. These events include:

1. The king's ghost appearing on the battlements of the castle.

2. The crowing of a cock at midnight, which is considered an ill omen.

3. The appearance of an armed head, a bloody child, and a crowned child.

4. The disappearance of Lady Macbeth.

5. The appearance of a doctor who claims to be able to cure the king's madness.

6. The appearance of a group of witches who prophesy that Macbeth will become king.

7. The appearance of Banquo's ghost at the banquet.

These events create a sense of unease and tension in the castle and foreshadow the tragic events that are to come.