how to interpret 内緒で買ってこなくちゃ


Without further context, what would be the best way to interpret this
sentence?  
内緒で買ってこなくちゃ ...

• 内緒 is secret  
• 買ってこなくちゃ means must buy  
I know there are another meaning for 買う such as to value/to provoke. But I'm
quite clueless. Is this a kind of idiom/metaphor ?




> I have to buy it in secret...!

Perhaps the speaker is talking to someone about a christmas present or
birthday present. Or they need to buy something in secret so that the other
party doesn't know they are buying it.




> I have to buy it in secret...!

Perhaps the speaker is talking to someone about a christmas present or
birthday present. Or they need to buy something in secret so that the other
party doesn't know they are buying it.

