  We report the discovery of a barium blue straggler star (BSS) in M67,
exhibiting enhancements in slow neutron-capture ($s$-) process elements.
Spectroscopic analysis of two BSSs (WOCS\,9005 \& WOCS\,1020) and 4 stars
located near the main-sequence turn-off using GALAH spectra, showed that
WOCS\,9005 has a significantly high abundance of the s-process elements
([Ba/Fe] = 0.75$\pm$0.08, [Y/Fe] = 1.09$\pm$0.07, [La/Fe] = 0.65$\pm$0.06). The
BSS (WOCS\,9005) is a spectroscopic binary with a known period, eccentricity
and a suspected white dwarf (WD) companion with a kinematic mass of 0.5
M$_\odot$. The first `sighting' of the WD in this barium BSS is achieved
through multi-wavelength spectral energy distribution (SED) with the crucial
far-UV data from the UVIT/\textit{AstroSat}. The parameters of the hot and cool
companions are derived using binary fits of the SED using two combinations of
models, yielding a WD with T$_{eff}$ in the range 9750--15250 K. Considering
the kinematic mass limit, the cooling age of the WD is estimated as $\sim$ 60
Myr. The observed enhancements are attributed to a mass transfer (MT) from a
companion asymptotic giant branch star, now a WD. We estimate the accreted mass
to be 0.15 M$_{\odot}$, through wind accretion, which increased the envelope
mass from 0.45 M$_{\odot}$. The detection of chemical enhancement, as well as
the sighting of WD in this system have been possible due to the recent MT in
this binary, as suggested by the young WD.
