  Magnetic frustration, arising from the competition of exchange interactions,
has received great attention because of its relevance to exotic quantum
phenomena in materials. In the current work, we report an unusual
checkerboard-shaped scattering anomaly in $\rm FeGe_2$, far from the known
incommensurate magnetic satellite peaks, for the first time by inelastic
neutron scattering. More surprisingly, such phenomenon appears as spin dynamics
at low temperature, but it becomes prominent above N\'eel transition as elastic
scattering. A new model Hamiltonian that includes an intraplane next-nearest
neighbor was proposed and attributes such anomaly to the near-perfect magnetic
frustration and the emergence of unexpected two-dimensional magnetic order in
the quasi-one-dimensional $\rm FeGe_2$.
