case of the missing pointer in C

A pointer has been disappearing in Visual Studio C. I call the following line:
return addVal(fp, value, root);

which calls this:

struct node** addVal(FILE** fp, int value, struct node** root){
FILE* rfp = *fp;
fprintf(rfp, "%d\n", value);
return insert(value, root);
}


and that's all that's important, because root disappears when I get to the line:
FILE* rfp = *fp;

the structure of root until that line is:
root = 0x0012fd74
*0x0012fd74 = 0x00346f90
*0x00346f90 = node
node.value = 2
node.next = 0x00000000

the structure of fp is:
fp = 0x0012ff48

starting at that line, root is displayed as:
root = 0x0012fd74
*0x0012fd74 = 0xcccccccc

root was passed into the function containing the return statement from main().