\begin{tikzpicture}
    \node[draw, rectangle, fill=gray!50] (DEAD) at (-2,0) ;
    \node[draw, rectangle, fill=gray!50] (DEAD2) at (10,0) ;
    \node[draw, circle] (A) at (0,0) {A};
    \node[draw, circle] (B) at (2,0) {B};
    \node[draw, circle] (C) at (4,0) {C};
    \node[draw, circle] (D) at (6,0) {D};
    \node[draw, circle] (E) at (8,0) {E};

    \draw[->] (A) -- (DEAD);
    \draw[->] (B) -- (A);
    \draw[->] (B) to [bend left=30] (C);
    \draw[->] (C) to [bend left=30] (B);
    \draw[->] (C) to [bend left=30] (D);
    \draw[->] (D) to [bend left=30] (C);
    \draw[->] (D) -- (E);
    \draw[->] (E) -- (DEAD2);

    \draw[->] ([yshift=4ex]C.north) -- ([yshift=4.5ex]C.south);
\end{tikzpicture}