Writer’s trip by wagon taking in grand prison like Alcatraz? (9,3)

'alcatraz?' is the definition.
Both the answer and definition are singular nouns.
Maybe there's a link between them I don't understand?

'writer's trip by wagon taking in grand prison' is the wordplay.
I cannot really see how this works, but
'wagon' could be 'cart' (cart is a kind of wagon) and 'cart' is present in the answer.
'grand' could be 'g' (G is short for grand as in a thousand) and 'g' is present in the answer.
'trip' could be 'ride' (eg a trip in a car) and 'ride' is located in the leftover letters.
'prison' could be 'pen' (both can mean an enclosure) and 'pen' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

'like' acts as a link.

Can you help me to learn more?