CLAUDIUS      How long hath she been thus?

OPHELIA        I hope all will be well. We must be patient. But I cannot choose but weep to think they would lay him i’th’ cold ground. My brother shall know of it. And so I thank you for your good counsel. Come, my coach! Goodnight, ladies, goodnight. Sweet ladies, goodnight, goodnight.

[Exit.]

CLAUDIUS      Follow her close. Give her good watch, I pray you.

[Exit Horatio.]             (4.5.67-74)

How long hath she been thus? Claudius is concerned, appalled, but perhaps calculating too; who else has seen and heard her like this? what degree of damage limitation is going to be called for? Ophelia’s receding into empty politeness, the calm, placatory nothings of the good girl, repeating her long-learned lessons, especially those about grief, about loss; small talk over a funeral tea: I hope all will be well. We must be patient. Then it breaks out, first in agony, a child puddle-jumping into the harsh details of death: but I cannot choose to weep to think they would lay him i’th’ cold ground. Why, why? Deep shock at the oddness of it, the cold ground, cold. And then anger, even threat, and this is what worries Claudius: my brother shall know of it. Oh yes. I’m not always going to be alone with this, alone and powerless.

But she gathers her dignity, her in-her-very-bones politeness, knowing her place (daughter of Polonius) even if it can be tinged with bitter sarcasm: and so I thank you for your good counsel. (NO ONE has been looking out for her.) Come, my coach! A fantasy of leaving a great ball, a party—a fantasy of being able to leave. Goodnight, ladies, goodnight. Sweet ladies, goodnight, goodnight. An easy, uneasy laugh if this is directed to Claudius, but again it shows Ophelia’s isolation, especially if a production hasn’t supplied silent waiting gentlewomen for Gertrude. Ophelia is so alone; no ladies for her, and Gertrude is wrapped up in son, husband(s), and herself.

Claudius is on it: follow her close. Give her good watch, I pray you. Don’t let her out of your SIGHT. Yes, Ophelia’s a danger to herself—but she’s also a time-bomb. The suggestion that it’s Horatio who follows her is editorial, but in keeping with his character.