History
Originally the acorn locket was a birthday gift from Nancy Whitehead to Doreen Green; however, through the use of some time-travel high jinks, an older version of Doreen gave her locket to her younger self. This created an interesting time paradox in which Nancy can place a message in the original locket and it will instantly appear in the future locket the present-day Doreen has.[2] Nancy used this messaging system when Doreen was mysteriously teleported away from the Negative Zone, separating her from her friends.[1]
Nancy's message to Doreen from the Negative Zone.