  It is an open problem, posed in \cite{SoCG}, to determine the minimal $k$
such that an open flexible $k$-chain can interlock with a flexible 2-chain. It
was first established in \cite{GLOSZ} that there is an open 16-chain in a
trapezoid frame that achieves interlocking. This was subsequently improved in
\cite{GLOZ} to establish interlocking between a 2-chain and an open 11-chain.
Here we improve that result once more, establishing interlocking between a
2-chain and a 10-chain. We present arguments that indicate that 10 is likely
the minimum.
