We propose to conduct a unique and very efficient Pa-beta imaging (1.4hrs science time!) of the best-studied galaxy cluster in formation, called "Spiderweb" protocluster, at z=2.16, with the NIRCam F405N filter. Our primary goal is to map the entire star formation activities across this starbursting protocluster, and within individual galaxies therein, by spatially resolving the dust-enshrouded star forming regions. We will unveil all the star forming activities down to a SFR of 3.5 solar masses per year, free from dust extinction, making a complete census of the protocluster (core). By mapping the SFR(Pa-beta)/SFR(UV) ratio within the galaxies in combination with the existing HST/ACS data, we will pinpoint the locations of dusty star-forming regions within the young cluster galaxies, - for a subset of members even matching at a similar spatial resolution of 1kpc ALMA dust continuum imaging. Taking advantage of the multi-wavelength, ancillary data available for the target field, we will calibrate the different star-formation indicators such as H-alpha, Pa-beta, dust continuum and rest-UV to NIR SEDs and we will determine the star-formation mode of each member galaxy. Simultaneously for free, we will observe with F115W (rest-U) and F182M (rest-V) at the SW channel of NIRCam, to map the distribution of quiescent and star-forming regions (and stellar mass surface density) for >100 known cluster members (out of which 61 are z-spec confirmed). The proposed Pa-beta imaging - as this line falls luckily in F405N - is the most powerful, unbiased approach to reveal the complete picture of the stellar mass assembly process in this young protocluster environment at cosmic noon.