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We present spectroscopic follow-up observations of CR7 with ALMA, targeted atconstraining the infrared (IR) continuum and [CII]$_{158 \mu \rm m}$line-emission at high spatial resolution matched to the HST/WFC3 imaging. CR7is a luminous Ly$\alpha$ emitting galaxy at $z=6.6$ that consists of threeseparated UV-continuum components. Our observations reveal severalwell-separated components of [CII] emission. The two most luminous componentsin [CII] coincide with the brightest UV components (A and B), blue-shifted by$\approx 150$ km s$^{-1}$ with respect to the peak of Ly$\alpha$ emission.Other [CII] components are observed close to UV clumps B and C and areblue-shifted by $\approx300$ and $\approx80$ km s$^{-1}$ with respect to thesystemic redshift. We do not detect FIR continuum emission due to dust with a3$\sigma$ limiting luminosity L$_{\rm IR} (T_d = 35 \rm \, K) <3.1\times10^{10}$ L$_{\odot}$. This allows us to mitigate uncertainties in thedust-corrected SFR and derive SFRs for the three UV clumps A, B and C of 28, 5and 7 M$_{\odot}$ yr$^{-1}$. All clumps have [CII] luminosities consistentwithin the scatter observed in the local relation between SFR and L$_{\rm[CII]}$, implying that strong Ly$\alpha$ emission does not necessarilyanti-correlate with [CII] luminosity. Combining our measurements with theliterature, we show that galaxies with blue UV slopes have weaker [CII]emission at fixed SFR, potentially due to their lower metallicities and/orhigher photoionisation. Comparison with hydrodynamical simulations suggeststhat CR7's clumps have metallicities of $0.1<\rm Z/Z_{\odot}<0.2$. The observedISM structure of CR7 indicates that we are likely witnessing the build up of acentral galaxy in the early Universe through complex accretion of satellites.

ALMA reveals metals yet no dust within multiple components in CR7