  We present a model of partial compositeness arising as the IR limit of a
SU(4) gauge theory with only fermionic matter. This group is one of the most
promising ones among a handful of possible choices allowing a symmetry breaking
pattern incorporating custodial symmetry and a top partner candidate, while
retaining asymptotic freedom. It is favored for not giving rise to lepto-quarks
or Landau poles in the SM gauge couplings. The minimal UV theory consists of
five hyperfermions in the anti-symmetric representation and three in the
fundamental and anti-fundamental. The IR theory is centered around the coset
SU(5)/SO(5), with top partners in the fundamental of SO(5), giving rise to one
composite fermion of electric charge 5/3, three of charge 2/3 and one of charge
-1/3. Electro-Weak symmetry breaking occurs via top-quark-driven vacuum
misalignment. The top quark mass is generated via the mechanism of partial
compositeness, while the remaining fermions acquire a mass via a standard
quadratic coupling to the Higgs. We compute the top and bottom quark mass
matrix and the Electro-Weak currents of the composite fermions. The model does
not give rise to unacceptably large deviations from the SM Z\to b \bar b decay
width.

High Energy Physics - Phenomenology