It isn't a JSONObject. It isn't a JSONArray. What is it?

I have not been working with JSON very long. I have the following response and I'm struggling to understand how to call the details of the "Topic". I thought it was a JSONObject, but Android's logcat is telling me JSONObject["Topic"] not found.

[{"Id":1,"TopicId":1,"UserGuid":"C214ED74-07A7-409E-84FF-AF0457CF581A","Topic":{"Id":1,"AdminUserGuid":"C214ED74-07A7-409E-84FF-AF0457CF581A","Title":"Test Topic 1","AccessType":"public"}}]
 

Any help is greatly appreciated.

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