Going to a passage whose name is stored in a variable

I'm trying to use a variable to store the name of a passage and then use that variable to create a link to that passage, but the resulting link takes me to a passage with the variable's name, instead of the passage whose name is stored in the variable.

The link looks like

[[Inventory][$returnDest to passage()]]

and then the Inventory page contains

Last visited passage: $returnDest

[[Done|$returnDest]]

If I visit it from my Home Base page, it correctly prints out "Last visited passage: Home Base", but the link takes me to a passage named $returnDest instead of the Home Base passage.

I found the How do I get around return and back getting me into a loop thread, but the difference there is how it's setting the variable, not how it's being called, so I don't understand why I'm not getting a link to the passage I want.