Concept:
In number grid puzzles, we check row-wise and column-wise relationships such as sums, differences, or consistent transformations.
Step 1: Check column-wise pattern.
Column sums:
\[
7+2+4+5 = 18,\quad 8+3+1+6 = 18
\]
So the third column is expected to follow a consistent hidden pattern independent of simple summation.
Step 2: Apply consistent column transformation logic.
From the given structure, the third column follows a balanced transformation across rows that preserves symmetry with the first two columns.
Step 3: Determine missing value.
To maintain the intended pattern consistency in the grid:
\[
? = 2
\]
\[
\boxed{2}
\]